West Ham United have confirmed that Manuel Lanzini will be out of action for up to six weeks with a quadriceps injury.
The Argentine midfielder sustained the problem in training last week and will now have a period of recovery after undergoing a scan on Monday.
Lanzini, who is currently on a season-long loan from United Arab Emirates outfit Al-Jazira Club, has netted four goals and added one assist in 12 Premier League appearances this term.
The 22-year-old could miss as many as seven league fixtures, including matches against Swansea City, Aston Villa, Liverpool and Southampton.
West Ham take on Stoke City at Upton Park on Saturday.