Sometimes you just have to know when to let go.

After dropping almost two total yards per rush in the last three years (3.3 from 5.2), it became easily apparent to most football fans — and very, very apparent to fantasy football guys — that LaDainian Tomlinson was washed up. So kudos to Dean Spanos and A.J. Smith of the Chargers for releasing the former stud running back.

It’s sad, but true. The signs of decline were there in ’08 and even more so in ’09 — Tomlinson had no more than 96 rushing yards in a single game this past season, and even if you throw in receiving yards, he amassed 100 or more total yards from scrimmage just twice.

So after what was reportedly an amicable parting (so says SI.com’s Peter King), Tomlinson will hit the open market. He and his agent, Tom Condon, will make their pitch to the other 31 teams in the league, which will be heard one of two ways:

On one hand, L.T. is a former NFL MVP, a four-time first team All-Pro selection and a member of the All-Decade team. He has the all-time NFL single-season records for total touchdowns and rushing touchdowns (31 and 28). He had 18 consecutive games with a rushing touchdown and an eight-consecutive game span with multiple touchdowns. Opposing safeties saw their reflection in his tinted bubble visor and trembled.

On the other hand, he’ll be 31 years old by the time the 2010 season starts. He’s already spent nine years in the NFL as a running back, which is like spending nine years getting hit by Volvos every Sunday for six months. Sure they’re not life-threatening hits, but they add up over time. By now, Tomlinson is still healing from bruises he received in 2007, and I’m sure his bruises are still recovering from bruises. Opposing safeties will rarely get a chance to see his tinted bubble visor because he will rarely make it into the secondary.

My advice to the massive audience of NFL front office guys I entertain every Wednesday morning: Go with the latter view.

Right now, Tomlinson is like the former prom queen at your 20-year high school reunion. Sure, the idea of dating her was tantalizing, but Jimmy Maresh had like 20 more varsity letters than you, so it was out of the question. Now that she’s a bit haggard, alone and low on self-esteem, it’s the perfect time to get in on that action, right?

Unfortunately, once the drunken euphoria fades and you realize she no longer resembles the brown-eyed cutie in the slutty-but-fashionable dress you remember, the regret sets in. Except in this case, the regret comes at the cost of $12 million over three years.

For proof, just look at L.T.’s backfield partner on the All-Decade team, Shaun Alexander. Alexander was on the same level of stardom, winning an MVP, and he held the single-season TD record before Tomlinson. And of course, after signing an eight-year, $62 million contract as a 28-year-old running back, he promptly became injured seemingly every other game.

Since signing that contract, Alexander put up about 1,600 yards and 11 touchdowns; or about one full season’s worth of production spread over four seasons. Almost no matter the skill level, running backs just get too hurt to be productive after 30.

Jamal Lewis had 500 rushing yards this past season at age 30. Jerome Bettis averaged 697 yards per season after hitting 30 and even Emmitt Smith couldn’t average 1,000 yards a season in his 30s.

Regardless of the decline that sets in for tailbacks after they enter their fourth decade of life, there are already rumors the Vikings could sign Tomlinson as a backup to Adrian Peterson. Current Minnesota backup Chester Taylor is a free agent, so why not sign a potential hall of famer?

Taylor’s value was in his pass-catching abilities, and the fact that, as a backup, he doesn’t get beaten like a redneck’s wife every game. Tomlinson is a fine pass-catcher himself, and reportedly wants to win a championship, so he might accept the second-fiddle role to A.P.

But is that really how he wants to win a title? At least when Jerome Bettis came back to try for a ring it was with the team he’d been with for a decade. And the chances Tomlinson even gets close to that storybook ending are pretty slim — partially because they’re riding on the play of another past-his-prime legend who isn’t sure he’s playing in the fall either.

It would be silly for Tomlinson to play the “last hurrah” card and waste away while getting 500 rushing yards over the next three seasons. Not only would it be sad, but also it would be a disservice to the teams who would misguidedly still expect greatness from him. I won’t rule out the possibility that L.T. comes back with one more great season, but unlike 57 percent of ESPN’s SportsNation thinks, he’s not a No. 1 back right now.

In my mind, Tomlinson is a hall of famer even without a ring. It’s not his fault he played in the AFC at the same time Peyton Manning’s Colts averaged 12 wins a season and Tom Brady was making the playoffs his personal bitch. Every decade has its great back, and Tomlinson owned the 2000s. Why tarnish what was a great legacy by allowing him to be a shadow of his former self for a couple more seasons?

Adam is a junior majoring in just journalism. Would you take a flier on L.T., or should he just retire? E-mail him at [email protected]