Uruguay midfielder Torreira was injured in the first half of the Gunners' 2-0 FA Cup fifth-round win over Portsmouth at Fratton Park after a strong challenge from James Bolton.

Torreira was taken from the field on a stretcher and Gunners head coach Arteta offered an update after the game.

"Lucas was very sore and is in a brace. He will be assessed in a few days and then we will know more," Arteta said.

Sokratis Papastathopoulos and Eddie Nketiah were on target either side of half-time as Arsenal survived a sluggish opening 45 minutes to ultimately book a comfortable route to the quarter-finals.

Nketiah was one of several youngsters again afforded an opportunity by Arteta, who is enjoying working with the Gunners' fledgling stars.

"I'm really pleased with them [the youngsters]," he said. "I'm enjoying working with the players. They deserve a chance. It's always a risk but they're worth the risk."

Arteta also praised Reiss Nelson, who was the architect of both of Arsenal's goals.

"We have pace in a few players up front. Reiss [Nelson] is a special player and can eliminate players one-on-one," the Spaniard said. "He's been out for a while but he's back now and he showed what he's capable of doing."