West Ham striker Michail Antonio has been involved in a road traffic accident, the Premier League club said.
In a statement, West Ham said: "The thoughts and prayers of everyone at the club are with Michail, his family and friends at this time."
The club said they would "issue an update in due course".
No details of the player's condition or further information about the incident have yet been given.
West Ham face Wolves in their next match in the Premier League on Monday (20:00 GMT).
Antonio, 34, joined West Ham from Nottingham Forest in 2015 and has since scored 68 goals in 268 league appearances for the club.
Several clubs including Premier League sides Everton, Southampton, Fulham and Brentford have replied to West Ham's statement on X, external sending their best wishes to Antonio.
More to follow.