Arsenal boss Mikel Arteta is unsure whether Sead Kolasinac will return this season.

The Bosnia international injured his shoulder in Sunday's win over Everton.

"He is seeing the specialist today and we will know more this afternoon," Arteta said ahead of Thursday's clash with Olympiacos.

"But yes, he was in pain, it's a difficult area and we are not very positive about it.

"Hopefully, yes [he will play again this season]. But I don't know. It's depending on whether he's dislocated it and if he needs surgery or not. We will know more this afternoon, hopefully."