The Hammers centre-forward has been one of David Moyes' key men since the Scot returned to the club, scoring 28 Premier League goals since the start of the 2019-20 campaign.
However, the Jamaican international has had regular problems with injuries and his fitness, which has stopped him from being ever-present for Moyes.
Other than Antonio, the East London outfit are bereft of options in the striking department, with the likes of Jarrod Bowen and Nikola Vlasic asked to deputise up-top.
Sebastian Haller was signed in 2019 to offer that depth, but the Frenchman struggled to find his feet in England.
He was sold to Ajax last year and is now the top goalscorer in this season's Champions League with 11 goals.
And, after selling Haller, McCoist believes that the Hammers 'need some help' in forward areas and has urged them to sign a striker in the summer.
"I think the players need a hand, they need some help," McCoist told talkSPORT.
"They need reinforcements, they need to strengthen.
"Everybody's talking about it and the majority of West Ham fans come on the phone lines and tell us the same thing.
"They say they're happy with the job Moyes is doing, but they really need to strengthen in [the striking] department.
"Antonio, as good as he is, he's been terrific, he's had a terrific season but, I've got to say, I've had a look at him and he's maybe looking a little bit jaded, which is understandable.
"He needs a hand."