In Spring Training 2007, Diamond's velocity was up and down, and he couldn't figure out why. An MRI revealed a slight tear in his elbow, and on March 20, 2007, Diamond had Tommy John reconstructive elbow surgery.
That led to 14 long months of rehab, which was extended when Diamond fell on a sprinkler head in the outfield and injured his left ankle. At the end of 2008, Diamond needed surgery to take out two bone spurs and remove cartilage damage and some scar tissue in his ankle. That type of thing will affect your ability to pitch.
"I'm healthy," he said in an interview last month in Mesa, Ariz.
On Friday, Diamond, 26, heads to Mexico to join the Mexicali team and take pitcher Jeff Samardzija's spot on the roster. He's hoping a strong showing will earn him an invitation to the Cubs' camp this spring.
"Two surgeries in two years and a couple subpar performances, and I really couldn't figure anything out," Diamond said after his last instructional league game for the Cubs. "Now, I'm starting to get things with [pitching coordinator Mark] Riggins, and I'm on a good path right now."
He has his former coach, Randy Bush, to thank for the opportunity. Bush, the head coach at University of New Orleans from 2000-04, is now the assistant general manager to Jim Hendry, and sold the Cubs on giving Diamond a chance.
"I recruited him out of high school, and he pitched for me for three years," Bush said Monday. "I watched him grow from a freshman who couldn't get anybody out, to a sophomore who filled a larger role on the team, to the 10th pick in the country.
"He's just a high character, hard-working, outstanding human being," Bush said. "It's one of those things where you're so comfortable with the person and know what kind of person you're dealing with that you want to give him every opportunity to get back to where he was."
Diamond has been tested, and not just physically. The oldest of three children, he was in the Minor Leagues in 2005 when Hurricane Katrina slammed into New Orleans. Most of the people he knew lost everything. The Rangers let him go back two days after the storm hit, and he brought gasoline for generators and water to drink. He helped as much as he could, and then packed up his family to stay with him in his new home in the Dallas area. Diamond had just closed on it, and his parents, brother and sister all moved in.
After the family left and returned to New Orleans, Diamond's new home became a refuge for some of his New Orleans friends who needed a place to stay and regroup.
He took them shopping, bought them clothes, made sure they had home-cooked meals. Diamond did a public service announcement to help raise money for hurricane victims. Card collectors gave him boxes of baseball cards to take back to children who may have lost all their toys, "just so they had something," Diamond said.
Today, his family and friends are safe. His father is working in New Orleans, and his business is doing well. Diamond is married and the father of a nine-month-old boy.
The relief work hasn't stopped in his hometown, but it's on such a huge scale now. If needed, he's there.
"It's going to come back," Diamond said of New Orleans. "It's just going to take awhile."
The same can be said of Diamond. In his last outing in the final instructional league game, he struck out five and gave up one hit over three innings.
"I felt really good because I didn't walk anybody," said Diamond, sitting in the shade near the Cubs' Fitch Park facility. "If I can do that, I'll be tough to beat."
Pitching is his focus. He's been working on a curve, which he used to throw with the Rangers until they put more emphasis on power. Riggins has stressed the need for more variety in velocity, and he wanted Diamond to add something slower with a break to get hitters to back off his fastball. In Mexico, he would like to pitch five or six innings per start to build up his arm for Spring Training. Diamond can't wait for February.
"I want to show [the Cubs] exactly what they have," he said.
He also wants to show the Rangers they made a mistake in letting him go.
"I've always been the guy growing up, and they say, 'Yeah, he's good, but we think these guys are better,' " Diamond said. "I've always liked being that underdog, castaway. It's a little bit of a wake-up call to get designated like that. It's baseball. It's a game sometimes that when you least expect it, it'll bite you in the butt. You get comfortable somewhere and that's not always the best thing. Now I'm in a new situation and doing my best to feed my family."
He's got a clean slate.
"The only person who knows me is Randy Bush," Diamond said.
Bush never lost track of his former player and didn't hide his interest in conversations with Rangers general manager Jon Daniels and assistant GM Thad Levine. When it came time for Texas to make some decisions regarding its 40-man roster, Levine contacted Bush, and the Cubs claimed Diamond.
Bush used to own some batting cages in New Orleans, which is where he first met Diamond. The two joke now that Bush wasn't much of a hitting instructor.
"I've known him since I was 10, 11," Diamond said of the Cubs executive. "He owned a baseball facility in New Orleans. I took hitting lessons from him. Those worked out great -- I'm now pitching.
"When I was a freshman, [Bush] told me, 'Your money is going to be made from 60 feet, 6 inches,'" Diamond said.
He has hit some lows. Hurricane Katrina wiped away personal belongings, but those things can be replaced. The elbow surgery took away his career for more than a year. Now, Diamond flashes a megawatt smile at the thought of everything he has to look forward to in 2010.
"You never know in baseball," he said. "I go through college, and my old college coach now goes up to the front office of a Major League club and it's a good connection to have. When you perform and put everything on the line for somebody, they appreciate that. It shows what kind of person he is to put his faith in me again and give me another chance."