Burnley striker Ashley Barnes will see a specialist to determine the full extent of a troublesome groin injury.
Barnes, who has struggled with the problem for several weeks, sat out last week's FA Cup win against Peterborough and is expected to miss Saturday's Premier League game at Chelsea.
The Clarets' bid to put a miserable Christmas period behind them has also been hit by news that fellow striker Jay Rodriguez and defender Phil Bardsley could both miss out through illness.
"We'll almost definitely be missing Barnesy," said Dyche, whose side have lost their last three league matches.
"He's been going on with things and trying to get through a period with an overuse injury.
"Bardo and Jay-Rod are both down ill. They have been since Monday, so it's obviously a deeper thing than just a bug.
"They're not in today so we'll see how they come through that and whether they're available tomorrow. The doctor is seeing them today.
"We keep getting nearly back and then we get another knock. Sometimes that's the way it is, but we carry on regardless."
Johann Berg Gudmundsson (hamstring) is still out, but Dyche had better news regarding Chris Wood (hamstring), who is likely to feature at Stamford Bridge, and Ben Gibson (groin), who is back in training.
Dyche has repeated in recent weeks that he is not expecting much transfer activity at Turf Moor during the January window and his side's injury setbacks are unlikely to force his hand.
"It doesn't change much really," he said. "You've got to have the money, that's the starting point – I'm still not clear on what's available and what will be available.
"The players have to be available though. You can have all the money in the world, but if players aren't available or the other club don't want to sell, or contracts can't be agreed etc, etc – it's a very tough business.
"Money is a massive help, but other things all have to align, it's not just about the money."
Burnley hope to use the momentum gained from their FA Cup win against Peterborough after recent defeats to Everton, Manchester United and Aston Villa.
The Clarets have lost six of their last eight league games and sit four points above the relegation zone, but Dyche insists his side's fortunes can quickly change.
"The reality of the Premier League is a tough Christmas is really about one result and that was the one we lost to Villa," he added.
"If you beat Villa people could say, weirdly, that we had a good Christmas, on 27 points and through in the cup.
"The Premier League is different like that. One game can mean everything in a different view point every week."
