The San Diego Chargers have never been married to their best players. They are one of the few teams unafraid to make the hard choices in letting good players go for nothing in return.

It’s worked for them, too.

After the 2005 season, San Diego bid adieu to quarterback Drew Brees.

While Brees has been a record-setter in New Orleans — his 5,069 passing yardage total this season was second in NFL history — it’s hard to argue with the Chargers’ decision to commit to Philip Rivers. Rivers led the NFL with a 105.5 passer rating this season, throwing 34 touchdowns and only 11 interceptions. The fact that he wasn’t voted to the Pro Bowl–and Brett Favre was–is a travesty.

Then after last season, the Chargers committed to veteran LaDainian Tomlinson, letting Michael Turner leave in free agency. Turner had a better season than LT, but not by much. Turner had 1,740 yards from scrimmage on 384 touches for Atlanta, while LT went for 1,536 on 344 touches.

This off-season, it’s running back Darren Sproles who becomes a free agent, and the Chargers should make every attempt to re-sign him.

Running backs, I realize, are a dime a dozen, and spending millions on one is foolhardy in most cases.

In 2006, only months after he had scored a then-record 28 touchdowns and earned the league MVP award, Shaun Alexander signed an eight-year, $62 million deal that included $15.1 million in guarantees. The Seahawks cut him during the off-season, and he currently is unemployed. Was Marion Barber worth the seven-year, $45 million the Cowboys committed to him during the off-season? Rookies Felix Jones and Tashard Choice cost less money, and they combined for more total yards (1,367) than Barber (1,302), who had only 29 total touches in the final five games because of a dislocated toe.

The Denver Broncos, until this season, have gotten by with whatever back they drafted late, and Houston’s Steve Slaton and Choice showed this season that a good back can be had after the first round.

So the Chargers don’t need to break the bank for Sproles. It would cost them $8 million to franchise Sproles, and he isn’t worth that. No running back is aside from Adrian Peterson.

But the Chargers can’t afford to let Sproles go.

LT isn’t getting any younger. He claims his injuries are unrelated to his age, but the facts say otherwise.

He had never been hurt until last postseason when he hyperextended his left knee in the divisional playoff game. In the Chargers’ final two postseason games, Tomlinson had 11 total touches for 54 yards.

Tomlinson now has a severely strained groin that limited him to five carries for 25 yards and a touchdown in Saturday night’s 23-17 overtime victory over the Indianapolis Colts. He might not play the rest of this postseason and could require off-season surgery.

Tomlinson has never missed a game because of injury.

“He wanted to go (Saturday),” Chargers coach Norv Turner told reporters in his Sunday news conference.

Sproles will carry the Chargers the rest of this postseason, giving them a chance to figure out how much he’s worth to them.