INDIANAPOLIS — In his 18th NFL season, Lions coach Jim Schwartz knows something about player personnel. This week’s NFL Combine is hardly his first.

In his opinion there are two positions where the players are the toughest to judge.

“I think historically linebackers and tight ends are very difficult to judge because every team uses those guys in so many different ways. What you see in college isn’t necessarily what they’re going to do in the NFL,’’ Schwartz said.

“... When they’re being asked to do something that may be totally different than what they did in college, that’s a hard evaluation,’’ the Lions coach added.

That said, the Lions drafted two starters at those positions last season and got it right — linebacker DeAndre Levy and tight end Brandon Pettigrew. The two were among five rookies who started the majority of the games last season.