EDEN PRAIRIE, Minn. -- Minnesota Vikings left tackle Riley Reiff (ankle) and tight end Kyle Rudolph (ankle) may not be available for Sunday's game against the Cincinnati Bengals.
Both players were initially listed as "doubtful" on Friday's injury report ahead of Week 15, but Rudolph was upgraded to questionable Saturday.
Rudolph was held out of practice all week, while Reiff returned in a limited capacity on Friday.
Reiff injured his ankle in the third quarter at Carolina and was replaced by reserve tackle Rashod Hill, who started the game at right tackle. Hill prepared throughout the week at left tackle in the likely event he is called upon to start over Reiff.
Earlier Friday, Minnesota placed tight end Blake Bell on injured reserve with a shoulder injury and promoted Kyle Carter from the practice squad to the 53-man roster to add depth at the position. Zimmer didn't list specifics about Bell's injury but said he will eventually have to have surgery.
"I don't know what happened. He hurt his shoulder," Zimmer said. "I don't know exactly what happened. I didn't ask what play he got hurt on or anything like that."
If Rudolph is out Sunday, the Vikings would have two tight ends active: Carter and David Morgan, who came out of the concussion protocol this week.
Rudolph averaged around six targets per game through the first 13 weeks and has been the Vikings' top red zone scoring threat, scoring six of his seven touchdowns this season inside the 20-yard line.
Minnesota is confident Morgan could pick up Rudolph's duties.
"David is ready to go," offensive coordinator Pat Shurmur said. "He's played a lot of football for us in really all of the groupings. He's played in a single tight end sets, double tight end and three tight end sets, so he knows what to do."
This is the first time all season where the Vikings have listed a player as "doubtful" before a game. Cornerback Mackensie Alexander (ribs) was ruled out for Sunday, while linebacker Emmanuel Lamur (foot) is listed as questionable.
Despite a longer injury report than usual, the Vikings do get two starters back on the offensive line. For the first time since Week 8, Mike Remmers is not on the final injury report after dealing with a concussion from Weeks 8-12 and lower back issues for the past two weeks. Also back in Week 15 is rookie center Pat Elflein, who missed the Panthers game with a shoulder injury after 12 consecutive starts.