West Ham United have suggested that defender Carl Jenkinson will be sidelined for some time with a "significant injury".
The 23-year-old suffered the complaint to his left knee while conceding a penalty for a foul on Sergio Aguero during Saturday's 2-2 draw with Manchester City at Upton Park.
"Unfortunately, it appears that Carl has suffered a significant injury and he will be assessed by a specialist in central London on Wednesday," read a statement on the club's official website.
Jenkinson is on loan with the Hammers from London rivals Arsenal.