I don't know if Keith Rivers can play middle linebacker — I don't know if the Lions know if Rivers can play middle linebacker — but I do know if Rivers is there at 15 in Saturday's NFL draft and the Lions take him, there's a good chance they'll do so with an eye on converting him to middle one day.

Rivers is widely considered the top linebacker in the draft. He played on the weak side all four years at USC, starting the last three and doubling as a back-up rush end as a freshman. He played some middle backer at the Senior Bowl with mixed reviews. He's a beast with a 42-inch vertical jump and a 4.51-second 40-yard dash.

But the Lions are set for the foreseeable future at Rivers' natural WILL linebacker position with future Pro Bowler Ernie Sims. The strong-side linebacker position doesn't serve as big a purpose in the Tampa 2 defense, and Lions coach Rod Marinelli ready admits it's generally not worth a first-round pick.

From Monday's pre-draft press conference: "Usually the SAM position is not generally a guy you'd want to take in the first round, but you might see more into the guy, a way to get him on the field early, too."

There's two things about that. First, a few weeks ago Marinelli and president Matt Millen offered contrasting comments about whether a rookie can start immediately at middle linebacker. The answer is yes, of course, but Marinelli said it would be difficult and indicated he'd prefer his rookie to learn the SAM position first. Was he talking with Rivers (or Tennessee's Jerod Mayo, another prospect who projects both inside and outside depending on who you believe) in the back of his mind? It's possible.

Second, Marinelli believes firmly in the power of doubles. He doesn't necessarily expect to hit a home run with his first-round pick, but he needs that player to be an above-average contributor for a decade in the NFL. Rivers will be that, we just don't know at what position.

This may be moot. Most projections have Rivers coming off the board before the Lions draft. But Rivers blogged about his trip to Detroit last week, said he was "really impressed," and I'm quite sure he's Marinelli's type of player. If he slips to 15, I bet he ends up a Lion.