Barker hit the stage with Machine Gun Kelly on Wednesday in St. Louis, Missouri, with plans to join his friend for the remaining dates on his Mainstream Sellout tour. Kelly wrote on his Instagram Stories earlier that day that Barker was going "against his doctor's orders AND with a broken thumb" to perform.
The 46-year-old Blink-182 alum joined in the excitement on social media, posting on Twitter, "I’m impregnating the entire crowd at the @machinegunkelly show tonight," adding that he was suffering from both "a broken thumb and torn tendons."
This isn't the first time Barker has joined MGK on stage since his health scare this summer. He previously hit the stage in mid July at Kelly's Los Angeles show at The Forum while wife Kourtney Kardashian looked on.
He also conquered his fear of heights while ziplining on a family getaway last week.
"I went in for an endoscopy Monday feeling great," Barker wrote on his Instagram Story at the time. "But after dinner, I developed excruciating pain and I have been hospitalized ever since. During the endoscopy, I had a very small polyp removed right in the very sensitive area, usually handled by specialists, which unfortunately damaged a critical pancreatic drainage tube. This resulted in severe life threatening pancreatitis."
Luckily, however, this bump in the road only brought Barker and Kardashian closer together.
"Kourtney has dropped everything to make sure that Travis is quickly on the mend. Being newlyweds, they weren’t anticipating this, but after what Travis went through and what they went through together, it made them even stronger and more connected,” a source told ET after Travis was released from the hospital. “Kourtney refused to leave his side until she knew he was going to be OK and put a halt on everything, like filming and work commitments.”
While the couple continue to work toward their goal of having a baby together, a source told ET earlier this week that “Travis' health is top priority right now.”
"Married life has been amazing and the kids are all adjusted, and they are all living life to the fullest," the source added.