Manchester City manager Manuel Pellegrini thinks Kevin de Bruyne will play again this season after the the midfielder injured his knee in the League Cup semi-final win over Everton.
The 24-year-old Belgium international - and £55m club record signing - changed the game from the bench but in injury time fell awkwardly after a challenge.
"I'm optimistic he won't be out for the rest of the season," Pellegrini said.
"We'll see how important the damage is. It's not the cruciate ligament."
The City manager added: "The doctor thinks, but he cannot be sure, that it's a problem in his medial ligament.
"Kevin has been a very important player all season. Tomorrow [Thursday] we will have news but it is not a nice injury."
De Bruyne scored one goal and set up another to help City to a 4-3 aggregate victory over the Toffees and they will now face Liverpool in next month's Wembley final.
Everton goalkeeper Joel Robles later apologised on social media after he repeatedly tried to pick up De Bruyne from the ground as the game was in added time.
He tweeted: "I would like to apologise to Kevin de Bruyne for my reaction to his injury.
"In the heat of the moment I didn't realise he was badly hurt. I wish him all the best and a speedy recovery."
De Bruyne's Belgium team-mate Jan Vertonghen suffered medial ligament damage playing for Tottenham last weekend, and Chelsea's Belgian goalkeeper Thibaut Courtois missed three months of the season with the same injury last year.