Smith was hurt on the third play of San Francisco's 23-3 loss to Seattle. Trent Dilfer will get the start against the Ravens.
Carolina Panthers quarterback Jake Delhomme said he hopes a rigorous rehabilitation program will allow him to avoid undergoing season-ending surgery on his strained right elbow.
A week after coach John Fox said Delhomme would not need to go under the knife, the quarterback acknowledged surgery is possible.
"Maybe that could happen down the line. I don't know, and that's the God's honest truth," Delhomme said. "We don't know yet."
Middle linebacker Dan Morgan also revealed for the first time that he has a partially torn Achilles tendon and is out indefinitely.
Coach Tony Dungy was awaiting medical updates, yet acknowledged each of those players, along with linebacker Rob Morris and No. 2 tight end Ben Utecht, could be sidelined.
"All the guys that were hurt yesterday have a chance to be out, yes," Dungy said. "I'd have to say there's a chance they'll miss some practices or a game, so as coaches we have to plan for all of them to be out."
Harrison, an eight-time Pro Bowl receiver who ranks fourth on the NFL's career receptions chart, bruised his left knee against Denver and spent the final 2 1/2 quarters in the locker room. Sanders injured his ribs in the first half and Dungy said team doctors instructed him not to play Sanders in the second. Addai, last year's top rookie rusher, couldn't finish the game after taking a hard shot to his right shoulder.
The most severe injury, however, was to Morris, who sprained his left knee late in the first half when Broncos tight end Daniel Graham was blocking him. Morris immediately fell to the ground, removed his helmet and was then taken off the field on a golf cart.
"It's not an ACL, I do know that," Dungy said. "It's a tendon injury, but I don't know the extent of it."
An already banged-up Buffalo defense took more hits.
Backup linebacker Kevin Harrison is lost for the season because of a knee injury. Starting safety Jim Leonhard and starting cornerback Ashton Youboty are likely to miss next Monday night's game against Dallas.
Leonhard has started the last three games for Ko Simpson, who was placed on injured reserve with a broken ankle sustained in the season opener. Youboty has also started the last three games since Jason Webster broke his forearm in the Bills' opening day loss to Denver. Webster was placed on IR, as well.
Ellison, Wire and backup defensive end Ryan Denney (broken foot) all could return following the team's bye after the Dallas game.