Coach Chan Gailey described the injury to kicker Rian Lindell's right shoulder as "not good." Without being definitive, Gailey said Lindell either broke something or nearly had his shoulder pop out a day earlier in a 27-11 loss to the New York Jets.
Either way, it leaves the Bills (5-3) trying out replacements this week as they prepare to travel to play Dallas (4-4) on Sunday. Sitting in a three-way tie atop the AFC East, Buffalo plays its next three -- and four of its next five -- on the road.
Gailey ruled out Lindell from playing Sunday, but wouldn't say whether the injury was season-ending.
Lindell was hurt making a diving touchdown-saving tackle, tripping up Joe McKnight on a 59-yard kickoff return to open the second half. He was slow to get up and held his right arm in pain as he walked to the sideline. He hit a 24-yard field goal in the third quarter, but was held out in the fourth quarter.
He's not missed a game in his nine seasons in Buffalo, and ranks second on the team with 204 career field goals and 875 points.
As for Williams, Gailey said the player will visit a specialist this week to examine a nagging left foot injury that's forced him to miss the past three games. Gailey didn't rule out Williams' season being over.
"That is a possibility, I'm not going to say it's not," Gailey said, while adding Williams will not play Sunday.
Williams didn't address reporters Monday, but was spotted walking with a distinct limp in a hallway outside the locker room. He wasn't wearing the protective boot he had on for parts of the past two weeks.
Williams is a six-year starter coming off his first Pro Bowl appearance. Williams has been the defense's most consistent player, and was rewarded for that in August, when he signed a six-year contract extension potentially worth $39 million.
The injury has been bothering Williams since training camp. At one point, the equipment staff cut holes out of the back of his left cleats to help alleviate the pressure.
Bell will miss his fifth consecutive game, and said he was scheduled to meet with a doctor later in the day.
Kelsay aggravated the injury in practice last week and did not play against the Jets. He had only returned a week earlier after missing the previous two games.
The Bills made a roster move Monday, promoting tight end Mike Caussin off their practice squad and releasing defensive back Terrence Wheatley.
Caussin spent the final five games of last season on the Bills' roster, but did not play after being signed off Jacksonville's practice squad. He's spent this entire season on Buffalo's practice squad.
Gailey said Wheatley became the odd-man out with rookie cornerback Aaron Williams set to return to practice this week after missing five games with a chest injury.