Burnley midfielder Dean Marney will miss the remainder of the season after suffering an anterior cruciate ligament injury to his right knee.
Marney injured himself when tackling Mesut Ozil in the 74th minute of Burnley's dramatic 2-1 defeat to Arsenal at Emirates Stadium on Sunday.
Examinations have shown ACL damage that will keep the 32-year-old out of action for the foreseeable future.
"Dean's seeing a specialist today but unfortunately he has done his right cruciate, which is the one he did before," Burnley manager Sean Dyche said at a media conference to preview Saturday's FA Cup match against Bristol City.
"There's obviously a long period of rehab for that one but he's come through that once before so in a good/bad way, he knows the script.
"He knows how long the rehab is but it's a blow for him and a blow for us because he's been playing very well. You don't want to lose any player.
"He's been an important part of what we've achieved here over a number of seasons. He's a tough-minded man and knows he's got the full support of everyone here."
Dyche will not change his transfer plans as a result of Marney's injury as he was already preparing to bolster the squad before the window closes next week - Hull City's Robert Snodgrass one of the names linked with a move to Turf Moor.
"We were looking to strengthen anyway. I've made it clear we are always looking at the background picture, if you like," he said.
"Quite obviously, we're not the market leaders so we have to be aware of what might change in our own group.
"We don't work with a big number. We're roughly around 20 recognised first-team players and we have to be working constantly to see what's out there, what's available and what fits into our bracket."