Arsenal manager Mikel Arteta says the injury suffered by defender Riccardo Calafiori during the 1-0 win against Shakhtar Donetsk is “a bit of a worry”.
The Italian, who joined from Bologna in a summer deal worth up to £42m, went off in the second half of Tuesday’s Champions League game after seemingly twisting his right knee.
Arsenal are already without key attacking players Martin Odegaard and Bukayo Saka, while defender Jurrien Timber is also injured.
“He felt something, he could not continue playing,” Arteta said of Calafiori.
“It is a bit of a worry.”
The Gunners, who are third in the Premier League table, face league leaders Liverpool at Emirates Stadium on Sunday.
Calafiori started at left-back against the Ukrainian side and was heavily involved, playing 42 passes from an often tucked-in position.


Oleksandr Zinchenko was on the bench and appears an obvious replacement if needed at the weekend – although Arteta instead sent on youngster Myles Lewis-Skelly for Calafiori against Shakhtar.

Former Chelsea forward Chris Sutton says Calafiori will be badly missed if he cannot feature against Arne Slot’s Liverpool side.
Sutton told BBC Radio 5 Live: “It’s such an intense period.

“Injuries put pressure on the squad. Arsenal are missing key players such as Bukayo Saka and Martin Odegaard.