Manchester City winger Scott Sinclair is being treated in hospital for a blood clot on his shoulder.
Sinclair did not travel with Roberto Mancini's squad to face his former club Swansea after being taken ill during training on Friday but is understood to be in a comfortable condition.
The club confirmed the news on Twitter, and Mancini, speaking after the goalless draw in Wales, said: "Scott had a problem (on Friday). I don't think it is a bad situation and it is under control."
City expect to know more within 48 hours but the 24-year-old would appear unlikely to have any hope of playing a part in next Saturday's FA Cup final against Wigan at Wembley at the end of a frustrating first season with the club.
He moved to Manchester from the Liberty Stadium last summer but has made only two Premier League starts.