On September 1st, The Rangers' major-league core can expand to include any member of the team's 40-man roster. The team has already been bolstered by Pitcher Mark Hamburger and Center Fielder Leonys Martin. Rangers prospect guru Jason Cole gave us an in-depth look at the most likely minor-leaguers to spend the stretch run wearing Rangers uniforms. Jason runs the most comprehensive Rangers prospect site around,Lone Star Dugout. It's incredibly tough to evaluate prospects, but Jason knows this organization's minor leaguers better than anyone who isn't already a Rangers employee. If he doesn't have the answer, it's unlikely anyone does.

The most likely aspect of the team to be bolstered is the bullpen. Let s start by talking about the most high-profile relief prospect in the system, Tanner Scheppers. He s had a very up-and-down year. Is he finally healthy and does he have the command to be an effective option down the stretch?

As far as I know, Scheppers is healthy right now. He went through the nerve issue in his lower back earlier this season, which was causing some numbness in his leg. But he rehabbed the injury for awhile and regained the strength in his leg.

The command part that's the big question. I'm not sold that the Rangers will give him a look this season. Scheppers' pure stuff has not been an issue this year. He still features plus-plus velocity to go along with a sharp curveball. But when he was with Frisco earlier this summer, his fastball generally worked at the belt and higher, making him hittable. It was the same issue that hurt him down the stretch in Triple-A last season.

Since Scheppers re-joined Triple-A Round Rock on August 7, each outing has been different. He has had a couple of lock-down command games, pounding his fastball low in the zone and getting strikeouts with the curveball. But he has also elevated at times, and he walked four batters in two innings during his last appearance.

It's all about command for Scheppers. When he initially returned from injury around mid-summer, I think he could have made an impact if he was showing good fastball command. But now the Rangers have traded for two late-inning relievers, and I don't think he is needed right now.

Scheppers has taken a slight step back this season because the within-the-zone fastball command just hasn't been there for much of the year. He still has the stuff to pitch at the back-end of the Rangers' bullpen someday, and I still think he has a good chance to do that. But I highly doubt he'll get that opportunity in a pennant race this season.

Let s go on to kind of a similar arm... Pedro Strop has crazy stuff... gets a ton of Ks and keeps the ball down. But will he ever get over the yips and control issues which bothered him in the majors?

That's pretty much the million-dollar question. I had a talk with Pedro about this when he was initially sent back to Triple-A in early May. Strop's biggest issue in the major leagues is about controlling his adrenaline. He often enters games over-hyped, causing him to rush through his delivery. When he does that, his fastball command suffers and he either falls behind in counts or elevates his stuff. The dilemma is that it's hard to simulate such a high-pressure environment in the minor leagues, where the crowds are smaller and the stakes aren't nearly as high.

His stuff, like Scheppers', remains excellent. Strop's fastball has actually ticked up in the last couple months, as he's sitting in the upper-90s and even reached 100 mph during a recent outing according to the Newberg Report's Scott Lucas. His slider is a solid pitch. He has a wipe-out splitter, but Strop must be ahead in the count to use it. The splitter has so much late dropping action that he rarely throws it for strikes so when he was falling behind constantly in the majors earlier this season, his best secondary pitch was practically taken away from him.

I'm not entirely sure which Round Rock pitchers will get looks in the major leagues in September, but I don't expect any of them to play a major role. The acquisitions of Koji Uehara and Mike Adams have really strengthened the late-inning spots. But both Strop and Scheppers are guys that figure to compete for opening day bullpen jobs in spring training 2012, for sure.

Mark Hamburger is a lesser-known arm whose main claim to fame is a great last name. What kind of pitcher is he? Are his recent starts reflective of a different view on his role, or are the Rangers committed to using him in the bullpen?

The last question is a good one, and I don't really know the answer. Hamburger had never started a game in his professional career until recently, but the results as a starter have been excellent 16.1 innings, 9 hits, 2 runs, 3 walks, 14 strikeouts. He is succeeding and keeping manageable pitch counts because he does a good job of commanding a 90-96 mph fastball, which has some late life to it.

I still think Hamburger is likely a reliever because his secondary stuff lags behind the fastball. His slider has improved this season, though, as he's now throwing it in the upper-80s with a little more late bite. He is also mixing in a splitter. Most of Hamburger's success as a starting pitcher has come from his ability to command a plus fastball, though.

Hamburger may not project as a late-inning reliever because he doesn't really have a swing-and-miss secondary pitch, but he is beginning to look more and more like a big league-caliber arm that could pitch in middle relief.

Rangers fans got a brief look at Cody Eppley early in the year. Has anything changed since then?

Not a whole lot has changed, although Eppley has really struggled with control in his last two outings (and at times this season). In June and July, he issued 21 walks in 24.2 innings. After dominating through most of August, he has now walked five in three innings during his last two appearances.

Eppley still has an 88-91 mph fastball with lots of sink, and his slider is still very tough on righties they're hitting only .211 against him in Triple-A this season. With Darren O'Day's issues, Eppley and Johan Yan (another sidearming sinker-slider righty) will likely have an opportunity to fill the sidearming righty role coming into spring training next season.

Eric Hurley was the less-heralded fourth wheel during the days of the Danks-Volquez-Diamond DVD trio. He s mounting a comeback after sustaining a serious injury; can Hurley be a major league pitcher, or is the stuff not there anymore?

He can still be a major league pitcher, though his ceiling isn't as high as it once was. Hurley now projects as a potential back-of-the-rotation starter or long reliever, whereas he was more of a number three starter before injury. The good news on Hurley is that he shows more pitchability post-injury he does a better job of mixing his pitches and working all four quadrants of the zone. The down side is that the stuff isn't quite as good, and his command has been a little spotty this season.

It's important to mention that this is Hurley's first season coming off the shoulder and wrist surgeries. His stuff may improve next season (it may not), and the command should get better with more experience off the injury. His fastball now sits in the 89-92 mph range and can reach 93 mph at times. His slider and change-up have both been a bit inconsistent this season, showing flashes at times and looking flat at others.

While it's clear that Hurley has a better idea of how to attack hitters since the surgery, his pitch counts have been high in recent starts because he is struggling to hit his exact spots. The command needs to improve for him to be a major league-caliber pitcher.

Is Michael Kirkman a starter or reliever? Can Captain Kirkman get over his command issues or will he forever be a moderate-upside pitcher who walks 5 guys per 9?

I wouldn't totally rule out Kirkman as a starter just yet, but I think he's definitely more likely to be a bullpen guy. I also wouldn't be surprised if the command issues always linger a bit for Kirkman, but he shows flashes. Kirkman has really battled his delivery this season he is in and out of it from outing-to-outing, if not inning-to-inning. It has been tough for him, especially since he has struggled at times in Triple-A this season after winning the league's Pitcher of the Year award in 2010.

Kirkman still features 90-96 mph velocity with a wipe-out slider when he is on top of his game. If he locks down the delivery next season, he could emerge as a key power left-hander in the Rangers' bullpen. If not, he will likely continue to yo-yo between Triple-A and the majors, both tantalizing and frustrating the Rangers with his power stuff and inconsistency.

Jake Brigham, Justin Miller and Beau Jones are a few other candidates for promotion. Do any of them have a chance to make a potential playoff roster?

I don't think any of them have a chance at making a potential playoff roster this season, but they could all pitch in the majors at some point.

Jones, the lone player acquired in the Mark Teixeira trade yet to play in the majors, is a six-year free agent after this season if he's not added to the 40-man roster. When Jones joined the system, he was a lefty with plus stuff but struggled with command. Now, the raw stuff isn't quite as strong but he's a better pitcher. Jones locates an 89-92 mph fastball pretty well with a good change-up. He also has a curveball. He doesn't have crazy upside but I could see the Rangers giving him a late-season look to see if he's worth a 40-man spot over the offseason.

Miller is an under-the-radar arm who has really improved his delivery this season, leading to better stuff and a lot more strikes. At Frisco this season, his fastball is sitting between 93-96 mph and reached up to 99 during a recent outing. His slider is progressing and is starting to miss some bats. Miller is definitely a guy to watch for next season, and I'd bet that he gets on the 40-man roster after this season.

Brigham is a frustrating arm because the stuff is legitimate like Miller, his fastball ranges at 93-96 and bumps 97 on occasion. Both his hard slider and sharp downer curveball flash plus. Yet Brigham often works up in the zone with his fastball, making him more hittable than he should be given the raw stuff. He is Rule 5 eligible this season, and his inconsistency makes him a fringe 40-man roster candidate.

Between Miller, Brigham, Tyler Tufts and Fabio Castillo, the Frisco bullpen has four right-handers with fastballs that reach the mid-90s with some consistency. They may not help the Rangers this season but they are all worth keeping an eye on.

Will Leonys Martin be called up, or is it more important for him to get regular playing time at AAA?

Disclaimer: Jason wrote this before Cruz's injury on Sunday night, and obviously things have changed a little since the Rangers need an outfielder and he is the only viable option on the 40-man roster. I still don't expect Martin will get much regular playing time, but he could always change that by playing extremely well when he gets his chance.

If Leonys Martin is called up, I don't think he will be seeing much game action with the Rangers. In other words, I think it would be more about him getting experience in a major league clubhouse and seeing how things work in preparation for next season.

In my opinion, it's important to remember that Martin took almost a year off from playing games while he defected from Cuba, worked to establish residency, and signed with the Rangers. I think there's a fatigue factor settling in for him, playing on an everyday basis for the first time in awhile. I think the Rangers are more likely to give him a breather after the minor league season is over.

Despite the so-so results in Triple-A, I still think Martin is likely the Rangers' Center Fielder of the future due to his defensive skills and on-base abilities. Adjusting to the state-side game in terms of base running and such has been a challenge, especially in Triple-A. He isn't ready for the majors just yet.

Jason Cole is the premier source for Rangers minor league info. Make sure to check out his stuff at Lone Star Dugout.

Check back to this site on a regular basis... this is just the beginning! We're going to have a presence at every September Rangers home game and will continue to write our trademark analytical pieces.

Follow WFAA Sports on Twitter

Like us on Facebook

Read or Share this story: