The forward was forced off for the second game running, after scoring a spectacular goal in Saturday’s 1-1 draw with Manchester City.
Antonio underwent an initial assessment yesterday but the extent of the problem is still not clear and he will have a scan within the next 48 hours.
The 30-year-old has scored 11 times since the Premier League restart in June — with only Harry Kane netting more (12) in the same period — but his career has previously been disrupted by hamstring injuries.
The draw against City means the Hammers have taken eight points from the last four League matches and they will complete a hugely impressive spell if they can avoid defeat at Liverpool on Saturday.
David Moyes says his team are now showing their true form after a dismal opening-day defeat to Newcastle, while wing-back Arthur Masuaku says there has been a shift in mentality from last season. “I can feel it and I think last year we would have lost [against City],” he said.