Daniel Farke says the injury Louis Thompson picked up on Tuesday will mean the midfielder may be out of action for around four weeks.
Louis Thompson featured for just a few minutes in Tuesday’s game against Aston Villa after a collison with Alan Hutton forced the midfielder off with a shoulder injury
Farke said: “At the time it was pretty painful, he had to go to the hospital after the game on Tuesday.
“If he handles this [injury] in a professional way, we hope he will be back in about four weeks. It’s the second time this type of injury has happened to him, it happened in pre-season as well.
“I’m hoping he’ll be back in three to four weeks, we will find out if he needs an operation on Monday.”
City striker Teemu Pukki has missed City’s last two games after suffering a hamstring injury away on international duty for Finland.
Farke believes this weekend is too soon for Pukki, but hopes he will be returning to first team action soon.
“Tomorrow is a bit too early [for Pukki to return], he’s not back in team training yet but he may be back for the cup game, it’s not too bad,” said Farke.
There were no other major injury worries ahead of Norwich City's encouter with Brentford on Saturday.
“Tom Trybull got a hit on his toe and Max Aarons had some slight problems but both are available for tomorrow.
Both Alex Tettey and Ben Marshall are available after both being unavailable in Norwich’s previous game.