Arsenal may have beaten Leicester, but the win was marred by injuries to Alexis Sanchez and Aaron Ramsey on Tuesday night.
The Gunners boosted their hopes of a top-four finish with a scrappy 2-1 victory overs strugglers Leicester, but manager Arsene Wenger's immediate concern will be the medical status to two of his key players.
Sanchez, who has only just returned from a two-week lay-off with a hamstring strain, suffered a problem with his knee in the first half at the Emirates Stadium and had to be replaced in the 68th minute.
Ramsey came on as a substitute in the second half but lasted only nine minutes before going off with what Wenger suspected was a recurrence of a hamstring injury.
"Sanchez got a knock on his knee," Wenger said. "From the moment he got this knock, he was never really comfortable.
"I don't know for how long he will be out and whether he will be out or not. I haven't seen the doctor."
On Ramsey, Wenger added: "It looks like it (a recurrence of a hamstring injury). I don't know how bad it is yet. Just visually, it didn't look good - when a guy stops straight away and sits down, that's not good news.
"There's a recurrence now of a few muscular injuries and it's difficult - we haven't found out why."
Arsenal, who climbed up to fourth, next face Middlesbrough in the FA Cup on Saturday, before travelling to Crystal Palace on February 21 for their next Premier League commitment.
