Arsenal's 3-0 victory over Sheffield United came at a cost after winger Bukayo Saka suffered a thigh issue that could see him miss out on Thursday's crucial Europa League trip to Slavia Prague.
Saka limped off in the 69th minute of Sunday's Premier League win at Bramall Lane and Arsenal boss Mikel Arteta said the England international's fitness would be assessed in the coming days.
Arteta was already facing an injury crisis ahead of the Europa League quarter-final second leg, where Arsenal travel to the Czech capital as underdogs after a 1-1 draw in their home leg.
The Gunners are already without the injured defenders David Luiz, Kieran Tierney (both knee) and forwards Martin Odegaard and Emile Smith Rowe (both ankle), and Arteta said they cannot afford to lose anyone else.
"He [Saka] had discomfort in his thigh and it's the last thing that we need because we're missing some big players at the moment and we don't want to lose another one," Arteta said.
"I don't know the extent [of the injury]. Hopefully, it's not that serious."
Captain Pierre-Emerick Aubameyang missed Sunday's win due to illness but Arteta said he hoped the Gabon striker would be available for Slavia.
"He was unwell yesterday, he could not train, he could not be available today but hopefully in the next day or two he will be feeling better and he will be available to get picked," he said.
Alexandre Lacazette scored twice and Gabriel Martinelli added another on Sunday as Arsenal moved up to ninth place in the league, while Sheffield United stayed rooted to the bottom after a 25th league defeat of the season.
Blades interim manager Paul Heckingbottom put on a brave face in the wake of his team's forlorn hopes of avoiding the drop.
"We can't feel sorry for ourselves," he said. "Seven more games and we won't be given anything. The players know they are playing for everything.
"These are the moments that make you hungry as a football manager and I will make sure the players feel that way."