Aaron Lennon will miss Saturday’s trip to Arsenal with a knee injury.
Clarets boss Sean Dyche was waiting to hear whether the problem, suffered against former club Spurs at Wembley on Saturday, required surgery.
But the former England winger faces a spell on the sidelines, just as Dyche’s squad looked like returning to full strength.
Dyche explained the situation: “Azza has had a knock on his knee, he’ll be a doubt now.
“I’ll find out more accurate information, but he’s got a chance of having an operation.
“He was down to see the specialist on Monday, and I’m waiting on news whether that’s been done or not, so we’ll find out more.
“He felt something in his knee at Spurs but finished the game, we had it checked out on Monday with the surgeon and a scan and stuff, and it looks like there was something, so they’ll deal with that accordingly.
“It’s nothing major, more on the cartilage.”
But Johann Berg Gudmundsson and Steven Defour have a chance of making the game at the Emirates, while Stephen Ward has returned to training, and Nick Pope came through a first outing since July with the Under 23s on Monday.
Dyche said: “Johann has had a bit of treatment today, but only for a knock, so we’re hopeful on that, he trained yesterday and today with us properly, and Steven is still getting a few niggles, so we’ll see how the week develops.
“That’s his calf, but I think we’ve got to be careful with his knee and his calf, to make sure that’s well.
“Popey is still making good progress, and Wardy is back in training for the first time.
“Still slightly moderated, but back on the grass with us as a group.
“He’ll need a bit of time yet, but it’s good to see him out there.
“And really pleased for Popey to get some game time. We’ll try to get him something further, whether that’s in-house or invite a team in, or whatever.
“We’ll try and get something organised because he does need games of course, and a couple of others probably need games as well.”