Kieran Tierney admitted he found his return to action in Arsenal's 1-0 defeat to Manchester City on Sunday physically difficult.
The Scottish left back had been out for over a month with injury, with his last start coming against Newcastle on January 18.
And Tierney, who struggled to cope with Riyad Mahrez and Kevin De Bruyne early on before improving as the game went on, spoke after the match of the challenge of getting his fitness back up to the necessary level.
'I was just knackered,' he told Arsenal's official website.