West Ham manager Glenn Roeder said David James could be out "for months rather than weeks" after picking up a knee injury in the friendly defeat by Holland.
It is suspected the England goalkeeper, a £3.5 million sterling signing from Aston Villa this summer, has damaged cruciate ligaments after colliding with Martin Keown during the 2-0 loss at White Hart Lane.
Roeder said: "He [the physio] has had a look at David this morning and he fears it could be months rather than weeks".
James is almost certain to miss making his Hammers debut at former club Liverpool on Saturday.
He said: "Martin collided with my leg and twisted my knee. I won't know how bad it is until the scan results are seen.
"It's unfortunate but these things happen. I'm happy that I am walking because when I got up on the pitch and tried moving the knee it locked which wasn't good".
PA