McGahee suffered the injury during Baltimore's 23-20 overtime loss Monday night against the Pittsburgh Steelers. He was limited to just one yard on his only second-half carry after injuring his ribs in the final minutes of the first half.
"He's got a rib issue," Ravens coach John Harbaugh said Tuesday. "We think he's going to be OK. We'll just have to see how the rib goes this week."
McGahee rushed for 41 yards on 12 carries in the first half, leaving the game in obvious pain with assistance from trainer Bill Tessendorf.
He played in the Ravens' second series of the second half, but left the game after a run up the middle.
"He was in pain," Harbaugh said. "He wanted to play."
The Ravens' leading rusher last season with 1,207 yards and seven touchdowns, McGahee said Monday night that he anticipates being ready for the 4-0 Titans.
"I got a little injury, but I'll be all right," McGahee said. "I took a helmet right on the side. It was real aggravating. From here on out, I'm getting ready for Tennessee."
Following a bitter loss to their chief AFC North rival, the Ravens now have a short week of preparation for the AFC South leaders.
Harbaugh gave the players off Tuesday and the team will begin practicing Wednesday.
"It's a big challenge, but it's something I think guys in the NFL learn how to do," Harbaugh said. "They move on pretty quickly. You know we'll probably be looking back at the game or the fans certainly will be looking back at the game for a couple of days, but the players are already over it and have already moved on to Tennessee. You have to."
Ravens outside linebacker Jarret Johnson was penalized for a critical personal foul when he shoved wide receiver Hines Ward out of bounds during the third quarter, an unnecessary roughness flag that cost Baltimore 15 yards and valuable field position. Three plays later, Steelers quarterback Ben Roethlisberger took advantage -- throwing a 38-yard touchdown pass to Santonio Holmes. "Obviously, I can't have that penalty," Johnson said. "It kind of gave them life. I just lost my head. I didn't realize I wasn't on the field. It's something to learn from. It hurts. I lost my cool and pushed Hines Ward. It's stuff you can't do."