The rest of us tend to forget, because forgetting is convenient, how fragile even the best of these pitching careers can be.

With all the fame and fortune now available in the game, with all the remedies known to modern medicine, there will still be cases in which a pitcher's arm simply will not allow him to continue in his chosen profession.

One day, he can be at the top of his craft. And the next day, he can be done. He might not know immediately that he is done, but this will be history's verdict.

The case before us this week is Brandon Webb, announcing his retirement at age 33 due to a right shoulder that simply will no longer accept the workload of pitching at the Major League level.

Not all that long ago, Webb was one of the very best pitchers in the game. In a three-year span, 2006-08, for the Arizona Diamondbacks, he was as good as anybody on the mound. He wasn't romanticized the way flame-throwers are, but his effectiveness was beyond dispute.

He featured the "heavy sinker." His off-speed stuff was much more than all right, but with that sinker, every hitter was a ground ball waiting to happen. In that three-year span, he finished first, second and second in the National League Cy Young voting. He was 56-25 for those three seasons, including 22-7 in 2008, for a club that was merely 82-80. His ERAs for those three seasons, while pitching his home games in a hitter-friendly facility, were 3.10, 3.01 and 3.30. In Wins Above Replacement for NL pitchers over these three seasons, he was first, second and fifth.

Webb was explosion-proof. Working against his sinker, elevating the ball for distance might have been a passing thought but it rarely became a reality. In 2007, for instance, for every nine innings pitched, he gave up 0.457 home runs. In other words, Webb was giving up one home run roughly every 20 innings.

So he was a fully established ace, a pitcher who could be counted upon for tonight's start and over the long haul. He was, of course, the D-Backs' Opening Day pitcher in 2009. But after four innings, he left that game and that assignment, with soreness in his right shoulder. He never pitched another big league inning.

"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.'"

Webb, being the competitor that he was, didn't go quietly or quickly. He had two shoulder surgeries and made repeated comeback attempts. He tried to return with Arizona in 2010 and then with Texas in 2011.

I remember one morning in Surprise, Ariz., with Webb throwing a batting-practice session. His sinker was moving again, his velocity was increasing, his off-speed stuff was working.

Webb came off the mound beaming. The Rangers, defending American League champs at that point, might have had a rotation opening. It was not a stretch to imagine Webb back at the top of his game, pitching for a Texas club that would once again be a big winner. Rangers manager Ron Washington, after observing Webb's performance, proclaimed that the issue of Webb pitching again in the big leagues was a question "of when, not if."

It certainly looked that way on that day. But when Webb's workload picked up, the shoulder once again couldn't take the strain. Webb was shut down once more.

He had another shoulder surgery, later in 2011. This winter, wanting to stay in the game, and with a rested right shoulder, Webb worked with Bryan Price, who had been his pitching coach with the D-Backs and is now pitching coach for the Cincinnati Reds.

Again, Webb had initial success in flat-ground throwing sessions, regaining his movement, controlling his off-speed pitches. But once again, as his workouts picked up intensity, "Just like the other times, my arm just won't let me do it."

He subsequently took time off, but with his shoulder still aching, Webb decided to announce his retirement this week. He had put in three years of work since leaving the mound in 2009, but there was no happy ending.

Only 33, Webb would like to find a way to remain in the game. There should be a place for him in baseball. He certainly knew how to pitch, knew how to compete, knew how to win, for that matter. In a more perfect world, he would still be pitching at the top of his game. But in this world, in this line of work, sometimes human fragility trumps even a Cy Young Award-winning talent.