Though saying the treatment he's received is helping, Johnson added he's not sure if it'll be enough for him to be ready on Sunday.
"Right now, I don't feel 100 percent confident in my shoulder," Johnson said before practice. "It's feeling better already. We'll just see what happens when game day comes."
Coach Chan Gailey said he hopes Johnson will return to practice and work out on a limited basis at least by Thursday.
Johnson did not return after being hurt in the fourth quarter of a 44-7 loss at Dallas last weekend. He was attempting to make a catch over the middle before being hit by cornerback Terence Newman, who was flagged for pass interference.
Johnson has four touchdowns and leads the Bills with 44 catches and 531 yards.
Slot receiver David Nelson missed practice due to a sore ankle. Nelson said he expects to practice Thursday.
Safety George Wilson also missed practice after hurting his neck last week, though Gailey said there's "a decent" chance he'll play.
On the bright side, veteran starting linebacker Chris Kelsay practiced after missing four of the past five games, including the past two, with a left calf injury. Kelsay is expected to return this weekend to bolster an anemic pass rush that has 15 sacks, 10 coming in a 23-0 win over Washington last month.
Rookie offensive lineman Chris Hairston also continued practicing and is expected to take over at left tackle after missing the past three games with an ankle injury.
Copyright 2011 by The Associated Press