After tearing the ACL in his right leg while planting to catch a popup during pre-game batting practice, Mariano Rivera’s career may be over. Before the season, Mariano Rivera announced that he’d made a decision about whether 2012 would be his final season. It was assumed that the choice would for the all-time saves leader to retire. Unfortunately, his last game may have come much earlier than he had planned.

If Rivera does call it quits, he’ll retire with a record 608 saves, which is only seven more than second place Trevor Hoffman but 130 more than third place. Unlike Hoffman, however, Rivera did it for a single franchise with constant championship expectations on his back for 17 years.

Despite 608, the number that looms largest for Rivera and the Yankees is 42. Its not just the number on the back of Rivera’s jersey or his postseason record of 42 saves. It’s also his age.

At 42, his rehabilitation will be long and strenuous. However, Rivera’s freak injury is par for the course that has been the Bronx Bombers season.

It’s only May 4th but Yankees pitchers have been dropping like the soldiers in Tom Hanks’ 2ndRanger Battalion. However, instead of Saving Private Ryan, Brian Cashman and Yankees management will seek to replace Major League Baseball’s all-time saves leader.

Rivera’s injury is just the latest in a long line of misfortunes to befall the Yankees pitching staff.

The Yankees have already had to demote Freddy GarciaPhil Hughes is till struggling and Joba Chamberlain, whom many believed was one the heir apparent to Rivera, will likely miss the entire season after injuring his ankle in a freak trampoline accident. Even Roger Clemens is back on trial in federal court.

In the grand scheme of things, Mariano Rivera’s injury signals the beginning of the end for the Yankees glory years.

Teixera may be 32 and A-Rod is just 36, however, athletes age in dog years under the bright lights of New York City.

Jeter has somehow avoided the effects of time and his .404 batting average leads the AL but the Yankees should look to stop handing out long contracts to older All-Stars and beginning getting younger before their clubhouse resembles a modern day Golden Girls reboot.

Soon a new crop of young leaders will have to emerge for the Yankees to remain atop or near the top of the American League.

However, unlike A-Rod, Teixera, Granderson and Sabathia, Jeter and Rivera were homegrown Yankees. They’re also the last remaining members of the Yankees late 90’s dynasty.

Hank Steinbrenner has been adamant that the post-Boss Yankees will be more fiscally responsible. Ultimately this requires the Yankees to show more commitment to their minor league system and emphasize better scouting.

Currently, the most highly touted recruit in the Yankees minor league system is the soon-to-be 40 year Pettitte.

In January, the Yankees traded Jesus Montero for 23-year old right-handed pitcher Michael Pineda. Two weeks ago, the Yankees announced Pineda would undergo season-ending surgery to fix a torn labrum in his throwing shoulder before he’d ever made a start in pinstripes.

Through 23 games as a Mariner, Montero is hitting .292 and is on pace to hit 24 homeruns and 78 RBI’s.

David Robertson will likely assume the role as closer for the remainder of the season but even if Rivera decides to return for 2013, the Yankees have to begin looking forward.

In Nick Swisher’s absence, the Yankees have turned to 35-year old Andruw Jones, who is hitting .225. A-Rod is still on pace to surpass Barry Bonds‘ as the home run king but he is clearly on the downside of his career as he struggles more and more to make contact and his power numbers decrease.

Besides CC Sabathia, the rotation doesn’t have a second ace that hitters fear.

While the Yankees lead the AL in home runs, the pitching staff ranks fourth in team ERA. They’re also currently fourth in the AL East.

The Yankees may have a short term fix in Robertson at closer but in the long term, the franchise is headed for a cliff filled with aging position players and an awful rotation.

Injury and age may have finally caught up to Mariano Rivera but it should serve as a warning to the Yankees that it may be time to invest in a more youthful future.