"I've tried everything -- I've worked with many different people, trying different things, so there's no second guessing," Webb said of his decision.
As it turns out, Webb's final game in the big leagues was Opening Day 2009, when he left the D-backs' game after four innings with some discomfort in his shoulder.
At the time, it didn't seem like a significant injury. Webb was coming off a season in which he was 22-7 with a 3.30 ERA in 34 starts and finished second in the NL Cy Young voting.
Two surgeries and several failed comeback attempts later, Webb finally acknowledged he was out of options.
"I was at the top of my game, at the top of the game and then it was just suddenly over," Webb said. "My dad said, 'At least you didn't have to struggle, at least you went out on top.' I was like, 'Yeah, but I would almost have rather have tapered off, because I think that would have been easier for me rather than just suddenly be done.'"
After trying to make comebacks with the D-backs in 2010 and the Rangers in '11, Webb thought he was done, but he had surgery in August 2011 to see if that might help.
Last season, he did not pitch and seemed to be all but retired. However, the love of the game and the desire to explore all options had him thinking maybe he could find a way.
Then this past November he ran into Reds pitching coach Bryan Price, who served in a similar capacity for the D-backs during Webb's run of success. Webb won the 2006 NL Cy Young Award and finished second in the voting in 2007 and '08 with Price as his pitching coach.
Price said if Webb was up for it, he would love to work with him to see if there was something left in his arm.
"If it was going to be anybody to work with, it would have been him," Webb said.
So starting just before Thanksgiving, the pair began working, and there were initial signs of hope during flat-ground sessions.
"I was spinning curveballs, my changeups were great, my movement was great and I thought maybe I could go back to where I was," Webb said. "But once I got close to getting on the mound and turning up the intensity, just like the other times, my arm just won't let me do it."
Webb tried taking a week off to see if that would help, but last Tuesday with his shoulder still aching, he decided there was nothing more he could do.
"It's frustrating, but it's a relief though, too," Webb said. "It's both feelings -- sadness because I'm definitely going to miss it, but also relief because I can stop worrying if I've done enough or tried hard enough. I was putting in all this time and effort over the last three years, and it turned out to be all for nothing."
Webb is not sure what his next step will be. His wife, Alicia, would like him to do something, he said, and he'll spend all the time he can with the couple's two young children, Reagan and Austin.
Baseball, though, still tugs at him, and his heart remains with the D-backs, who drafted him out of the University of Kentucky in 2000. It's the only organization for which he threw a Major League pitch.
"I don't know if I'm coaching material," Webb said. "I would like to do something in the game. What it is I don't know."
The D-backs would certainly like to talk to him about what that might be.
Team president and CEO Derrick Hall said he planned on giving Webb a little time to get past the decision, but then hopes to discuss a way to make Webb a part of the organization going forward.
"It's obviously a sad day," Hall said. "He had a wonderful career, and in my opinion, will always be a D-back. He provided our fans and organization with some great pitching memories. He was always a class act and represented the D-backs in the finest way. He's a wonderful father and husband and has always been a true gentleman."