Vikings running back Adrian Peterson was held out of Thursday's practice due to a lingering groin injury. Head coach Leslie Frazier said Peterson is expected to practice on Friday after missing consecutive practices.

Peterson has had issues with his hamstring and groin all season, but he leads the NFL with 1,208 rushing yards.

"It just tells you how amazing he is," Frazier said. "Not only does he play, but he plays extremely well. It's just incredible when you think what those injuries could for any position, less someone at running back."

Quarterback Christian Ponder still hasn't passed the NFL concussion protocol and Frazier said he will likely not have a role Sunday against the Ravens.

Wide receiever Greg Childs practiced again on Thursday, marking the first time he's participated in consecutive days. Frazier hopes Childs can practice again on Friday. The Vikings must make a decision by next week to either activate, release or place Childs on injured reserve.

"Childs has looked pretty good; he's made a lot of progress," Frazier said.

Frazier said tight end Kyle Rudolph (broken foot) hasn't progressed as fast as the team hoped. Rudolph was expected to miss 4-6 weeks. He will miss his fifth game on Sunday after suffering the injury against the Cowboys on Nov. 3.

Linebacker Larry Dean (knee) missed practice again. Defensive tackle Sharrif Floyd (illness) was also limited in practice.

VIKINGS-RAVENS INJURY REPORT
Vikings: RB Adrian Peterson (groin), LB Larry Dean (knee), QB Christian Ponder (concussion), CB Josh Robinson (chest), TE Kyle Rudolph (foot) and S Jamarca Sanford (ankle) did not practice Thursday. DE Jared Allen (finger) and LB Chad Greenway (wrist) were limited.
Ravens: LB Elvis Dumervil (ankle), S Brynden Trawick (ankle) and CB Asa Jackson (thigh) did not practice. DE Chris Canty (shoulder), WR Brandon Stokley (knee) and CB Lardarius Webb (abdomen) were limited.