Jack Wilshere and Wojciech Szczesny both suffered injuries and had to be replaced during Arsenal's Premier League defeat by Manchester United.
England midfielder Wilshere, 22, limped off with what looked an ankle problem after he was tackled by United defender Paddy McNair during the second half.
Wilshere attempted to run off the injury but was eventually substituted.
Gunners keeper Szczesny was then taken off after colliding with Kieran Gibbs in the lead up to United's first goal.
Arsenal manager Arsene Wenger said he does not expect the Polish keeper to have sustained a bad injury, but added he was unsure about Wilshere's ankle.