That much was clear just looking at Gilmore, who hung his head in the Heinz Field locker room following the Bills' 23-10 loss to the Pittsburgh Steelers on Sunday, his left wrist still noticeably swollen.
"It's not 100 percent, I wouldn't say that. It's sore after every practice, after every game," he said. "I'm just out there fighting."
For his first two games back, Gilmore wore a club over his left hand that essentially left him with one functioning arm. The club came off three weeks ago, but his play has still been noticeably impacted.
"I don't use it like I would use it if it was 100 percent," he said.
Gilmore was flagged for holding on the Steelers' opening drive, and later missed a tackle on receiver Jerricho Cotchery, springing a 26-yard catch-and-run.
Both of those plays can be explained in part by the wrist injury, but Gilmore appeared to be out of position for several other plays, with the Steelers finding success targeting his part of the field.
On one of those plays, Cotchery left Gilmore in his wake on a fade pattern for a 5-yard second-quarter touchdown.
"He came up and blocked me and then went out for a pass," Gilmore said. "He kind of lulled me to sleep a little bit on that play."
Not surprisingly, that was just how Steelers drew it up.
"[It was] a fall-asleep fade," Cotchery said. "We just try to lull the guy to sleep. Once he peeks [into the backfield], it's a touchdown."
Bills coach Doug Marrone was quick to defend Gilmore last week, when the Chiefs attacked him for most of the game. Marrone said Gilmore had the tough task of covering Dwayne Bowe and reacted similarly to Gilmore's performance Sunday.
"I think sometimes you have to give credit where credit is due," Marrone said. "Sometimes they are going to make a play. Cotchery is a good, veteran receiver. He made a nice move back there."
The problem, though, is that Gilmore is the Bills' top cornerback. As Buffalo's 2012 first-round pick, it's Gilmore's job to cover the best an opponent can offer and win consistently.
Injury or not, that hasn't happened lately. Under Mike Pettine, the Bills' defense requires strong man-to-man coverage to support blitzing and pressure, and if Gilmore isn't playing as well as he or the team would like, they will need to adjust.
"I'm getting better and better everyday. We're playing a lot of man [coverage]," he said. "That's what we like to do. That's what I like to do. So I'm trying to fight for my team."