It’s sometimes hard to believe that Alfredo Aceves, the forgotten man out of Spring Training who didn’t arrive in the Bronx until May last year, finished with the fourth most wins on the Yankees. He always seemed to enter the game at exactly the right time, and he ended up with 10 wins and just one loss.

In many respects, Alfredo Aceves’ 2009 campaign helps highlight a lot of statistical platitudes about pitching. Relief wins are rather meaningless when some of them come in extra innings and others are brought about by virtue of long relief, multiple-inning appearances. He did, as Steve Lombardi wrote at Was Watching over the weekend, vulture his wins.

As a Posnanskian aside, Aceves’ 2009 splits also show how pitchers’ numbers respond to luck. In the first half, he threw 43.1 innings, allowed 34 hits, walked nine and struck out 7.5 per 9 IP. His ERA was 2.49. In the second half, he threw 40.2 innings, allowed 35 hits, walked eight and struck out 7.3 per 9 IP. Despite allowing fewer home runs and sporting a WHIP just 0.065 higher in the second half, his ERA over those 40.2 innings sat at 4.65. Luck changed, and his ERA settled in at a respectable 3.54 for the season.

Basically, Aceves was an above-average reliever, Lombardi says, who won more games than he probably should have. As Steve rightly points out, the odds of Aceves doing that again are slim, and he says, “Let’s hope the Yankees aren’t banking a repeat of this from Aceves this season.”

Now, I don’t wish to denigrate Alfredo Aceves. He turned in a very respectable season for the Yanks after spending a month at AAA. He had a WXRL of 2.522 and an ARP of 12.9. By many respects, he was the Yanks’ third most valuable reliever in 2009 due to his high innings total and relatively high-leverage usage. He can get a ground ball; he can get a K; he can throw short stints or make long appearances. All in all, he’s a very good guy to have.

But the Yankees know Aceves’ limitations as well. His shoulder started barking in late July, and he seemed to hit a mid-summer wall. He was not very consistent in limited October use and, as any pitcher, fares better against less patient hitters. How will the Yanks use him in 2010?

Well, from the start, Aceves will see his spot on the depth charts bumped down a bit. The Yankees will, in all likelihood, head into 2010 with Mariano Rivera as the closer, either Phil Hughes or Joba Chamberlain as the primary setup man, David Robertson as the go-to strike out guy, Damaso Marte as the lefty specialist and Chad Gaudin as the primary long reliever. Aceves stands to be the sixth guy out of the pen and the Yanks’ seventh or eighth starter.

In the end, the Mexican Gangster adds some depth the Yankees’ bullpen. He does a good job of keeping hitters off base and generally keeps the ball in the park. He’s versatile and adopted well to different roles. With Javier Vazquez around, the improvement to Yanks’ pitching staff trickles down the bullpen, and the team should, if all goes according to plan, not need Aceves to swoop in and nab those vulture wins this year.

Above: Al Aceves pitches against the Orioles in July. (AP Photo/Kathy Willens)

When Alfredo Aceves made an emergency start on July 9 in Minnesota, he did so under a strict pitch count, and he quickly reached his 65-pitch limit. For Aceves, it wasn’t a season high. That total came in his season debut when he threw 70 pitches against the Red Sox on May 4. It was, however, a recent high at the time, and he hasn’t approached that figure since early July.

In the three weeks leading up to that start, he threw five and nine pitches on back-to-back days, had two days off and then threw 43 pitches. He enjoyed another two-day rest before throwing 33 pitches. Then he had four full days off and threw five and 35 pitches before a two-day stint on the bench. On July 5, four days prior to his start, he threw 43 pitches.

Since July 9, we’ve heard a lot about Aceves’ various physical ailments. In late July, he spoke of a sore shoulder, and he hasn’t been as effective after the All Star Break as he was before. Many pixels have been burned discussing Aceves’ usage and health, and late last week, Mike looked at how Aceves has had few clunkers that inflate his numbers. As Ace has been outpitching his FIP all season, Mike noted, this period of mediocrity could just be the ever-popular market correction.

After his poor outing against the Red Sox on Sunday, Aceves spoke to reporters about his well-being, and as Peter Abraham reported, Aceves is feeling banged up. “I think my body is adjusting,” he said of relieving.

Aceves had been a starter for his entire Mexican League career and last year with the Yankees. This is the first year he has pitched out of the bullpen, and according to Abraham, Aceves feel it has “taken a physical toll.” After recovering from his sore shoulder, Aceves is now dealing with a sore lower back. “It’s not perfect, but I can pitch,” Aceves said to The Journal-News reporter. “This is my job now. I think I’m going to be fine.”

While the Yankees, on a micro level, need Aceves’ versatile down the stretch, on a macro level, his complaints provide a glimpse into the world of starters-turned-relievers. As Phil Hughes and Joba Chamberlain have shown, good pitchers make for great relievers. It’s easier for a pitcher to use his best pitches in short stints. He doesn’t have to mix and match to fool hitters during the second or third time through the lineup.

Yet, that transition is not without its risks. For starters used to the physical toll of a five-man rotation — start, ice, rest, throw day, rest, start — life in the bullpen is of a different nature. Pitchers have to prepare to go long but may faced with a five-pitch or nine-pitching outing. They may get the call on consecutive days or on opposite ends of a calendar week.

As the Yankees confront the reality of Phil Hughes in the bullpen and Joba Chamberlain in the starting rotation, the coaches and training staff are well aware of the physical toll of relief work. It’s why they don’t want to put Joba in the bullpen to cap his innings. How they handle Aceves down the stretch should provide a glimpse into how they plan to approach Phil Hughes’ transition back to the rotation next year. Meanwhile, with a seven-game lead and a Magic Number of 32, the Yanks can afford to rest Ace as his physical ailments require. Better now than in October.