West Ham boss David Moyes admits they're unsure about Jarrod Bowen's back injury.

Bowen broke down in defeat to Wolves on Saturday.

"Jarrod's not with us, he's got an injury and he's not available to play tomorrow night," Moyes said ahead of tonightls Europa League quarterfinal clash with Bayer Leverkusen.

“We're not sure [on a timeframe] and I probably wouldn't be giving any dates of when we'll get him back. I couldn't give that at the moment.

“We think that when he got the knee, he's twisted and damaged a bit of something," Moyes explained. “They said it's like what a fast bowler gets, with the rotation. We think that's where the damage has come."