"I knew it was just a matter of time, because that's just the way I approach things," Diamond said. "Going into this, I just told myself to take it like it's any other thing I'm doing, and work just as hard on the rehab as the things I do during the season."
Diamond went into rehab knowing it was going to be one of the hardest things he'd ever done in his career, and he's maintaining that same steadfast frame of mind in his pursuit of making it to the big leagues.
Two starts in, things are looking up.
In his season debut on May 21 -- his first regular season start in almost 21 months -- Diamond was a little wild, walking four in 4 2/3 innings and surrendering six runs.
"Everybody likes to act like they aren't nervous, but I was nervous," Diamond said. "The butterflies were going crazy in there for the first inning, but I settled down."
However, a strikeout pitcher his entire career, Diamond hadn't lost his knack for the strikeout, fanning five in the brief outing. Diamond had no reservations about rearing back and firing his fastball.
"No trouble cutting loose, just trouble controlling it," Diamond said.
His confidence grew when the only pain he felt in his elbow the next day was normal "day-after" pitching soreness.
Facing the same Tulsa lineup a week later, Diamond was better in all facets, holding the Drillers to just one earned run in five innings, striking out seven and allowing three hits and two walks.
However, Diamond still has a ways to go in recovering the velocity he exhibited before his surgery.
By the end of the 2004 season, the same year in which Texas drafted him No. 10 overall, Diamond was rated by Baseball America as having the best fastball in the Rangers' system. Frisco pitching coach Terry Clark said Diamond was hitting 97 mph with regularity before he blew out his elbow.
On Wednesday, Diamond topped out at 94 mph before hovering around 90 mph near the end of his outing. Still, Clark is confident Diamond can regain his velocity and touch the 95-97 mph range before the end of the season.
Clark had his own professional pitching career put on hold by Tommy John surgery, and has been influential in Diamond's recovery from the surgery.
"Considering I've done what he did, we've had some long talks," Clark said. "We talked in the offseason about how his progress was going, just trying to get him to understand not to rush it. He's got plenty of time. He got a brand new arm, so he's going to pitch for a long time without ever hurting it again."
Clark has noticed that Diamond's curveball is much improved from prior to the surgery, thanks to a slight alteration in his mechanics.
From here on out, Diamond said he'll continue to pitch every fifth game, with his next start scheduled for Monday, but his spot in the rotation will be skipped on occasion to keep his innings down. If his velocity and command continue to improve and his innings are kept in check, he thinks he has a legitimate shot at pitching for the Rangers by September.
"I'd like to get there by the end of this year," Diamond said. "It seems like a pretty lofty goal, but if I'm throwing good and I have low enough innings, I think they'll give me a chance."