Newly-signed quarterback Daunte Culpepper is expected to get about two-thirds of the first-team reps in his first Lions practice today.

Culpepper officially signed with the Lions Tuesday and could start this weekend's home game against Jacksonville. Dan Orlovsky, who started the last four games, did not take part in the individual portion of Wednesday's practice that's open to the media but was on the field with a cast on his throwing hand. He said Monday he has a sprained thumb and was day-to-day, but the injury is believed to be more serious.

Drew Stanton, a second-round pick out of Michigan State last year, will get the rest of today's first-team reps. He has never taken a regular-season NFL snap.

Lions coach Rod Marinelli said Monday he hoped to use Wednesday's practice to get Sunday's starter ready. "It's hard splitting way too many reps," Marinelli said. "It's hard, very difficult."

On a teleconference with Detroit media, Jacksonville coach Jack Del Rio said "it'd be very tough" for Culpepper to start Sunday.

"I think it's possible, I think it'd be very difficult," he said. "It just depends on how much he could familiarize himself, how close some of the terminology is to some of the things he's heard in the past and whether or not he can get his footwork in order and his hots and his protections and all the different things you've got to work through at that position. There's an awful lot to that position so it would be a heck of a deal if he could pull it off."

Del Rio said the Jaguars haven't watched any film of Culpepper this week, but they know his skills and tendencies well. Assistant head coach Mike Tice coached Culpepper in Minnesota.