TAMPA, Fla. – On the surface, Buccaneers running back Doug Martin looks very expendable.

He’s coming off an unproductive season and the coaching staff seems to have big plans for Charles Sims in his second season. The Bucs should be able to get a decent draft pick in exchange for Martin. So why not deal him?

Because it would be a mistake. I’m not sure Martin ever gets back to being the 1,400-yard runner he was as a rookie in 2012. That sure didn’t seem likely last year when Martin gained only 494 yards and averaged 3.7 yards per carry. But some of that had to do with injuries and some of it had to do with poor blocking by the offensive line.

There’s no question Sims is a talent. He might be the feature back next season. But the Bucs still need Martin. In the current NFL, you need two quality running backs. Sims isn’t the kind of back who can handle 25 carries a game.

The Bucs need Martin to handle some of the carries. Yeah, they have Bobby Rainey and Mike James. But those two rarely played when Martin and Sims were both healthy last season. Rainey and James are special-teams players who can fill in at running back in a pinch.

Martin is more than that. When healthy, Martin still can be a productive back, especially if he gets some help from the offensive line.

Even if Sims is the main guy going forward, the Bucs still need Martin as insurance.