MLB

A-Rod facing age-old problem

If Alex Rodriguez were a free agent after this season what kind of contract do you think he would receive?

He is 35 now, just a year removed from hip surgery and in the midst of his worst full season. He is an acknowledged steroid cheat — something that was not known before he signed his two previous record contracts. So if he is clean now, then it can be assumed he will suffer age decline like most players; in fact, he might be going through that right now.

Rodriguez has reached a point already at which Joe Girardi feels it is vital to sprinkle in off-days and DH days to preserve a body that needs the breaks. A once gifted runner, Rodriguez has just two steals. One of the great righty forces in history, Rodriguez actually has a lower batting average against lefties (.207) this year than Curtis Granderson (.214).

PHOTOS: A-ROD HITS 600

Take all of that into account and does anyone think Rodriguez would receive a seven-year, $181 million contract? Well, that is what he has left after this season in base salary and pro-rated signing bonus. That averages to $25.85 million a year. Would you like to know the only multi-year contract in history that tops that average?

That would be A-Rod’s current contract with the Yankees that began in 2008 and averages $27.5 million a year. So just what remains on A-Rod’s deal would be a record contract for anyone else.

Which made his chase for 600 homers even more interesting. Because what if it provided some glimpse not only of A-Rod stressing to reach a milestone, but a window into what he might look like in years to come when he struggles more profoundly and for longer stretches?

Already in 2010 — with seven years left on that contract after this season — we see a Rodriguez hitting for less power, running way less frequently, needing more rest and being susceptible to southpaws. Do you think that will get better or worse in 2011? How about 2013? How about 2017, which is the final year of the contract, at which time Rodriguez will be 42?

Could he rebound? Sure, betting against a talented player is never a great idea. Remember that Rodriguez hit two homers and seven RBIs in his final regular-season inning last year to reach 30 and 100. He followed with a brilliant postseason. So maybe hitting that 600th homer Wednesday against Shaun Marcum will serve as liberation. With all the dents, Rodriguez still has the second-most RBIs in the majors; still remains a force that the Yanks are elated to have in their lineup at present.

But it would seem another hip surgery is as likely in his future as a whole season that evokes the best of his past; especially when you see so many days now when the fluidity is absent from a once graceful athlete.

Rodriguez needed three years to the day to hit the 100 homers necessary to go from 500 to 600. Do you think he will be at 700 on Aug. 4, 2013? He needs 163 homers to break Barry Bonds’ all-time record. Nine players in major league history have exceeded 163 from their age-35 season onward. But positions one and three on that list belong to Bonds and Rafael Palmeiro, whose late-career exploits are now soiled by ties to illegal performance enhancers.

Girardi said even during the worst of A-Rod’s struggles toward 600 that he never considered another cleanup hitter. Girardi cited sticking with Mark Teixeira when there were calls to oust him from the three spot. Now Girardi is enjoying Teixeira’s rebound. Teixeira, though, is five years younger than A-Rod.

It is just reality that sometime during the final seven years of his current contract Rodriguez will have to be moved from cleanup and almost certainly moved from third base and possibly from the starting lineup and potentially off the roster altogether. That will come at great cost both financially and psychologically to the team.

That should serve as caution for how the Yanks deal with Derek Jeter, who has an expiring contract, is a year older than A-Rod and is in the midst of his poorest season, as well.

It is possible that while reaching this milestone Rodriguez also showed what a millstone he might become in the near future.

joel.sherman@nypost.com