ARLINGTON, Texas (AP) Matt Harrison never really knew what it would be like when he started his comeback from spinal fusion surgery.
Still, the Texas Rangers left-hander never doubted that he would pitch again - and he's about to in the major leagues again.
Just more than 13 months after the spinal fusion that was his third back surgery over two seasons, Harrison is back with the Rangers and scheduled to start Wednesday night at home against Arizona.
''I think success for me was getting back on the mound. ... My biggest hurdle was getting back on the mound again,'' Harrison said. ''At this point, it's a matter of getting my mind right again to go out there and pitch in a big league game, and try to control my emotions as best as possible.''
The 29-year-old Harrison was activated from the disabled list Saturday, the deadline for the move after the end of his 30-day medical rehab assignment when he made six starts in the minor leagues. His last major league start was May 13, 2014, a game at Houston he left with back stiffness.
''It's just amazing to be at this point,'' Harrison said.
Harrison was coming off an All-Star season in 2012 when he won 18 games, part of a two-year span when he was 32-20 with a 3.34 ERA in 63 games, when he got a new $55 million, five-year contract. Harrison had never had any back issues before then, but has since made only six major league starts.
The lefty worked through back soreness during spring training in 2013 and lost his first two starts before two epidural injections. He eventually had two operations in nine days on a herniated disk in his lower back and missed the rest of the season.
The start of his 2014 season was delayed after back stiffness during spring training. He then made four starts before being diagnosed with a condition in which a vertebra slips out of position along with significant nerve irritation before the spinal fusion surgery in his lower back.
There is no known history of a major league pitcher coming back from that type of procedure.
''I feel good physically and mechanically. Just ironing out everything is the hardest part, and learn how to pitch with less (velocity),'' Harrison said. ''But I'm confident in myself and command the strike zone, be aggressive and get people out.''
Harrison is trying to follow teammate Colby Lewis, who had his own unprecedented comeback.
Lewis, the Rangers' most successful postseason pitcher, had surgery in July 2012 to repair a torn flexor tendon in his right elbow. His comeback from that was thwarted by the troublesome hip that had bothered him for some time before he had a resurfacing procedure in August 2013 that was just short of a full hip replacement.
After finishing strong last season, Lewis is 8-3 going into his start Sunday against the Los Angeles Angels.
''I hope I can be, I don't know if inspiration is the right word, to be a lot of different people, just with the hip. Matt can do the same thing with his back,'' Lewis said. ''A lot of people think we've got this done and it's going to limit me in certain things that I do for the rest of my life. I think what I've done and what he's done, it opens eyes.''