West Ham have been dealt a major injury blow with the news that goalkeeper Lukasz Fabianski has suffered a torn hip muscle.
The PA news agency understands the Pole, West Ham's player of the year last season, faces at least a couple of months on the sidelines.
Fabianski suffered the injury taking a goal-kick during West Ham's 2-2 draw at Bournemouth on Saturday, a result which lifted them to third in the table for 24 hours.
The 34-year-old was replaced by Spaniard Roberto, who joined West Ham on a free transfer in the summer.
Roberto, 33, had previously been limited to two appearances in the Carabao Cup and was hardly convincing as West Ham lost 4-0 at Sky Bet League One Oxford last week.
West Ham also signed David Martin, son of former Hammers defender Alvin, over the summer as third-choice keeper.
As recently as Friday manager Manuel Pellegrini described Fabianski as one of the best goalkeepers in the Premier League, so his absence will be keenly felt as West Ham attempt to stay in and around the top four.
The Hammers next host Crystal Palace at the London Stadium on Saturday evening.