Antonio had to come off in the first half of West Ham's 3-2 win at Wolves on Monday with a hamstring problem.
Antonio has undergone scans on the injury in his left leg and though the severity has yet to be officially confirmed fourth-placed West Ham fear he is set to miss a significant part of their eight-game run in and bid to finish in the Champions League places, reports the Daily Mail.
The concerns about an extended spell on the sidelines for Antonio come after key midfielder Declan Rice was ruled out for four weeks with a knee injury picked up on England international duty.
West Ham have also been missing centre-back Angelo Ogbonna due to an ankle problem and forward Andriy Yarmalenko following a knee injury, both since early February.
However Ogbonna was back in training on Wednesday while Yarmalenko has also stepped up his recovery by returning to light training.