General manager Martin Mayhew recently asked Jeff Backus about changing positions from left tackle to guard, a team source said. Backus, the same source said, is open to the idea.

It's not known whether the change will take place – Backus has started every game, 128 straight, at tackle since entering the league as a first-round draft pick in 2001 – but the fact that both sides are comfortable with the move gives the Lions more flexibility this offseason and might make it more likely they'll consider drafting an offensive lineman No. 1 overall.

Both Mayhew and new coach Jim Schwartz have expressed a desire to get bigger and more physical up front, and the Lions have a vacancy at guard after releasing Edwin Mulitalo last week. (Damion Cook, who shared the starting duties with Mulitalo last season, is scheduled to become a free agent.) The Lions return Backus, center Dominic Raiola plus the entire right side of a line (tackle Gosder Cherilus and guard Stephen Peterman) that allowed 52 sacks last year, second most in the league.

“Just because 4/5ths (of last year's starting linemen) are on the team right now doesn't mean that 4/5ths are going to be starting at the end of training camp when we go into next year,” Schwartz said Tuesday. “Like I said, those decisions haven't been made. It's way too premature to read too much into that. You want to have as many options open to you when you go into the season as you can. That includes experience, that includes guys that are familiar with the scheme and everything else.”

While most pre-combine draft projections have the Lions taking Georgia quarterback Matt Stafford with the first pick, three elite tackle prospects also are available in Alabama's Andre Smith, Baylor's Jason Smith and Virginia's Eugene Monroe. Last year, eight tackles went in the first round (including Cherilus) and the Dolphins took Michigan's Jake Long No. 1.

ESPN analyst Mel Kiper predicted last week that “by the eighth pick three offensive tackles are off the board” this year.