Antonio was due to feature in the Hammers' next Premier League fixture against Wolverhampton Wanderers at the London Stadium on Monday night.
However, West Ham have taken to social media platform X to issue a statement confirming that the striker has been involved in a car crash on Saturday.
"West Ham United can confirm striker Michail Antonio has today been involved in a road traffic accident," a club statement read.
"The thoughts and prayers of everyone at the club are with Michail, his family and friends at this time.
"The club will issue an update in due course."
No details of Antonio's condition or further information about the incident have yet been made public.
An image showing a silver Ferrari completely smashed in a woodland area has circulated on social media, but it is yet to be confirmed who was involved in this incident.
Antonio has featured regularly for Julen Lopetegui's West Ham so far this season, starting 11 of his 14 Premier League appearances and contributing with one goal and one assist.
The Jamaica international scored his only top-flight goal in a 4-1 home win over Ipswich Town at the beginning of October, and has since failed to find the net in his last seven outings for the Hammers.
Antonio joined West Ham in the summer of 2015 and has made a total of 323 appearances in all competitions, scoring 83 goals and registering 41 assists.
The former Tooting & Mitcham United, Reading, Cheltenham Town, Southampton, Colchester United, Sheffield Wednesday and Nottingham Forest player is West Ham's all-time leading goalscorer in the Premier League with 68 goals.
Antonio's former clubs are some of many who replied to West Ham's statement on X sending their best wishes to the striker.
More to follow.
Written by
Oliver Thomas