Lucas Torreira was stretchered off with an ankle injury in Arsenal’s FA Cup fifth round win at Portsmouth.
The Gunners booked their place in the quarter-finals of the competitions thanks to goals from Sokratis Papastathopoulos and Eddie Nketiah.
But the result was slightly marred by an early first-half injury to Torreira, who required oxygen and a stretcher.
The Uruguay midfielder was on the receiving end of a strong tackle from James Bolton, who appeared to win the ball.
After a lengthy stoppage, Torreira was replaced by Dani Ceballos in the 16th minute.
He is a major doubt for Arsenal’s home clash with West Ham on Saturday.
Arsenal boss Mikel Arteta revealed Torreira is in a leg brace and video footage showed the 24-year-old leaving the ground on crutches.
The Spaniard told BT Sport: “He was very sore, he’s in a brace at the moment.
“He’ll need to get assessed in the next few days and then we’ll know more.”
