Mikel Arteta says Alexandre Lacazette's hamstring injury will require a scan after the Frenchman was forced off during Arsenal's 1-1 draw against Fulham on Sunday afternoon.
The Gunners' top goalscorer has scored 17 goals in all competitions this season, having come into particularly clinical form over the past few games.
Lacazette, who is out of contract next summer and has been linked with a summer move away from Emirates Stadium, hobbled off on 70 minutes and was replaced by Eddie Nketiah who went on to score a late equaliser.
Arteta admits the news that the 29-year-old could be set for a spell on the sidelines comes at the worst possible time.
Pierre-Emerick Aubameyang is currently recovering from malaria, leaving Gabriel Martinelli and Nketiah as the main forward options right now.
"We don't know yet. He felt his hamstring," Arteta said after the game.
"We will have to see. He will have a scan probably on Tuesday to see the extent of the injury and the timeline to it.
Arsenal face Everton on Friday night before playing Villarreal in the first leg of their Europa League semi-final in Spain.
"I cannot tell you if it's going to be a week, two weeks, five weeks or six weeks. He felt something with his hamstring and we don't know the extent of it.
"We are all disappointed because we know the moment Lacazette is in."
