Manchester City forward Jack Grealish was injured and substituted after 30 minutes in Tuesday's Champions League playoff against Real Madrid.
Grealish crouched down in his own half and received treatment before being replaced by Phil Foden.
It was not immediately clear what had caused the injury, but the England international appeared to be holding his groin when talking to manager Pep Guardiola on the sideline.
Despite not being able to play on, Grealish was able to walk off the field and down the players' tunnel. He appeared to be walking with a slight limp.
Grealish moved to City from Aston Villa in 2021 in a then-British record £100 million ($139 million) deal.
With City, he has won three Premier League titles and a trophy treble in 2023 which also included the Champions League and FA Cup.
Grealish has endured a difficult campaign this year, making only six league starts.