Sam Allardyce questioned the decision to disallow an Enner Valencia header that cost West Ham a point against Aston Villa on Saturday.
The Ecuador striker nodded home a Nene cross in the second half at Villa Park to cancel out Tom Cleverley's opener, but he was adjudged to have been in an offside position.
Replays were inconclusive and Allardyce believes his player was being played onside by number of Villa's backline.
"We're not sure about the offside decision," he said after the 1-0 Premier League defeat. "The assistant is in a terrible position to give that decision.
"The only reason he's given that is because the two Villa players nearby are in front of Valencia, but there are three defenders elsewhere who we think are playing him on."
The disallowed goal meant West Ham have now only scored once in their last four games and Allardyce admitted: "Our cutting edge has been missing for many weeks. We don't have anybody who can score a goal.
"It doesn't matter how many chances we create, we're not scoring.
"We'll struggle to win a game between now and the end of the season if we can't score a goal."
