West Ham say striker Michail Antonio is in a stable condition and “conscious and communicating” after a road traffic accident.
In a statement, West Ham said Antonio is “currently under close supervision at a central London hospital”.
The Premier League club added: “At this difficult time, we kindly ask everyone to respect the privacy of Michail and his family.
“The club will make no further comment this evening, but will issue a further update in due course.”
Antonio’s road accident happened on Saturday afternoon in the Essex area.
In an earlier statement, West Ham said their “thoughts and prayers” were “with Michail, his family and friends”.
Antonio, 34, joined West Ham from Nottingham Forest in 2015 and has since scored 68 goals in 268 league appearances for the club.
West Ham face Wolves in their next match in the Premier League on Monday (20:00 GMT).