Fernando Forestieri and Joost van Aken are among the injury concerns as Sheffield Wednesday prepare for Sunday's Championship test at Brentford.
The Owls' first win of the season, 2-0 at League One Sunderland in the Carabao Cup last night, came at a price as centre-half van Aken hurt his ankle and limped out of the action in the second half.
Attacker Forestieri, a scorer in both of Wednesday's first two league games, picked up a groin complaint in last Saturday's 1-1 home draw with Hull City.
Both are being assessed by the club's medical staff today, along with striker Lucas Joao (groin) and defender/midfielder Morgan Fox (back) who, like Forestieri, missed the Stadium of Light clash.
"Joost van Aken must be a doubt," manager Jos Luhukay confirmed. "I don't know yet if for Sunday he is an option. On Friday we must see what players we have available.
"We must wait for tomorrow (Friday) and see what the diagnosis is. Taking him off wasn't a precaution. He had an injury and cannot play further in the game.
"Fernando is also a question. He had a problem on his groin but we hope that Fernando can play on Sunday.
"He had problems after the game on Saturday. We must be careful now but I hope that Fernando is an option for us at Brentford."
Luhukay selected a strong side to face the Black Cats but also managed to give game-time to five of Wedneday's under-23 prospects as goals from Marco Matias and Adam Reach secured a second-round tie with Premier League Wolves at Hillsborough.
"Sunderland have the quality of a Championship team," he said, explaining his decision to give starts to senior players like Tom Lees, Barry Bannan and Steven Fletcher. "They have quality as individual players and also as a team.
"I watched Sunderland's first two games and they made a good impression on me. This team should be very high in the league this season and could come back to the Championship next year.
"Of course, it is nice to get the first win of the season. It is important for the confidence and trust of the players. Sunday is a new game and we will have some changes in our team and we must look to see which players are 100 per cent fit."