West Ham midfielder Manuel Lanzini has been ruled out for up to five weeks with a knee injury, Slaven Bilic has confirmed.

The Argentina international injured himself while preparing to take part in the Rio Olympics and, having returned to east London to be assessed, is now set to miss the start of the Premier League season.

The Croatian manager said: "Unfortunately for us, Manuel Lanzini's injury is a blow. It's not a big injury but he can't play for the next four or five weeks."

A five week timeframe would see Lanzini return to fitness at the start of September but also rule the midfielder out of fixtures against Chelsea, Bournemouth and Manchester City.

Lanzini's absence represents a significant blow for Bilic, whose side will make their Olympic Stadium bow against NK Domzale tonight, as the 23-year-old is the second casualty of pre-season for the Hammers.

Aaron Cresswell is set to miss a significant chunk of the season after being injured during the club's tour of Austria with Bilic's attempts to bring in cover for the Englishman yet to yield results after Arsenal rejected West Ham's approach for Kieran Gibbs.