Arsenal will be without Ben White for a while after the defender limped off during their 2-1 win over Wolves on Saturday.
White, who recently returned from an injury layoff, started the Premier League clash against the bottom team.
He lined up in defence alongside William Saliba, who was playing for the first time in four games, after suffering an ankle problem.
But after chasing down a counter-attack, White pulled up with what appeared to be a hamstring problem.
He is now expected to miss their next game against Everton.
It remains to be seen how long the England defender will be ruled out for.