West Ham manager Sam Allardyce has been left counting the cost of the international break as both striker Diafra Sakho and midfielder Stewart Downing are doubts for the Premier League trip to Everton.
Downing had just earned himself a recall to the England squad following fine form in the Hammers' promising start, but suffered a knee problem in the first half against Scotland at Celtic Park on Tuesday night.
Sakho, who had netted six goals to help West Ham climb to fourth, was not able to take part in Senegal's African Nations Cup qualifier against Botswana on Wednesday because of a back injury, and will be assessed after his belated return to east London.
"If it is as serious as it was to miss the game completely, then we haven't got a lot of time to cure the problem," said Allardyce.
"If need be, we will wait until Saturday morning to see what he is like.
"Stewart came off with a knee problem in the England game, so we have to assess that.
"Some of the situations with today's demands on players is causing all managers throughout the Premier League huge problems regarding injuries.
"It is something we have to cope with as a squad, but it is disappointing that you come to face Everton and, through no fault of your own, you lose your players. That is the way it is today.
"We need to be very careful about our fixture list coming up and if we risk a player on Saturday, if it aggravates the injury even further, then we could lose him for two or three weeks, and if you do, you lose him for four or five games."
Should Sakho, signed from Metz in the summer, not be fit, then Andy Carroll could be in for a first start of the season having recovered from ankle surgery.
The England forward sharpened his match fitness when playing the full 90 minutes and scoring in a behind-closed-doors match against Fulham.
Allardyce said: "Andy is ready to start, but he is not 100 per cent fit.
"He is eager and ready to go, as is Carlton Cole, and we have Enner Valencia too, so we have good options now."