West Ham United boss David Moyes says he has concerns over Michail Antonio's form this season.

The 31-year-old forward has been playing for Jamaica during international breaks this term, having switched allegiances earlier in the campaign.

Moyes believes the long travel could be impacting Antonio's form and fitness.

"I've had concerns about it, yeah, because it's new to him," said Moyes, per Evening Standard.

"It's not something he's been doing since he was 21 or 22 or something like that.

"Obviously, they're long travels if you're going to Jamaica or Costa Rica or wherever it was. They're long journeys to play the games.

"I'll never stop anybody if they want to play for their chosen country."