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Friday 21 February 2020 21:17, UK
West Ham defender Ryan Fredericks faces a potentially long lay-off with a shoulder injury.
The full-back suffered ligament damage after colliding with Manchester City midfielder Rodri during Wednesday night's 2-0 defeat.
Fredericks, 27, will see a specialist before the club know the full extent of the injury.
Speaking ahead of West Ham's game at Liverpool on Monday live on Sky Sports, Moyes said: "I can't confirm exactly how long he is going to be out for but we know that he has damaged the ligaments in his shoulder and we're waiting on more advice to see what we think.
"Obviously we're doing everything we can to get him back as quickly as we can but I couldn't confirm at the moment whether it's surgery, I couldn't confirm if it's just going to be healing time, we're just waiting on another bit of advice.
With West Ham remain in the relegation zone following their defeat at the Etihad Stadium and other players recovering from injury, Moyes was asked whether there would be a temptation to rush Fredericks back.
"I don't think you ever want to play any players who are not fit or who are injured and I certainly won't do," he added.
"But, yes, we've got a need. We need them all back fit and we want them all fit.
"Obviously Ryan is important to us but we can't do anything if he's damaged his shoulder, we just need to see what the doctors and the medical people tell us.
Asked whether Fredericks would be back before the end of the season, Moyes replied: I hope so, but again I couldn't tell you.
"I'm still waiting for everything to get confirmed by the medical people."
Veteran Pablo Zabaleta is likely to be called upon again to deputise at Liverpool on Monday night.