Arsenal loanee Kieran Tierney could be out for more than a few weeks due to a new injury.

The Scotland international is spending the season out on loan at Real Sociedad.

While Tierney has impressed with La Real, he is set for a spell on the sidelines this month.

He had to come off during Copa Del Rey action on Tuesday night, with Real Sociedad manager Imanol Alguacil stating post-game:

"We're going to wait for the relevant tests, but it's clear with Kieran that it's a rupture in the hamstring.

"It's a shame, because we have left back Aihen Munoz out too and it's important to double up in positions because of the amount of games we're going to have to play. But I've never made excuses and I'm not going to start now."