Mikel Arteta admitted Riccardo Calafiori being forced off against Shakhtar Donetsk was a “bit of a worry”.

The Italian defender started the Champions League match but was replaced with 20 minutes remaining after stretching awkwardly and appearing to jar his knee.

Calafiori initially tried to continue after receiving treatment, but he swiftly signalled to the bench that he needed to be replaced and Myles Lewis-Skelly was brought on.

It is a major concern for Arsenal ahead of Liverpool’s visit to north London on Sunday, with the club now facing a nervous wait to assess the severity of Calafiori’s issue.

“Riccy I don’t know, he felt something,” Arteta told Prime Video.

“He could not continue playing, so bit of a worry.”

The Gunners are already short in defence heading into a crucial Premier League encounter against Liverpool, with William Saliba suspended after his red card against Bournemouth.

Takehiro Tomiyasu is out injured and Jurrien Timber remains a doubt too, having not been fit enough to make the squad in the two matches since the international break.

With Thomas Partey potentially having to fill in at right-back this weekend to allow Ben White to move into central defence, an injury to Calafiori would force Arteta into another reshuffle.

Oleksandr Zinchenko is fit but has not played for Arsenal since August, while Jakub Kiwior is another option at left-back. However, he too has had little in the way of first-team football, and it would be a huge test up against Mohamed Salah.