Manchester United defenders Chris Smalling and Phil Jones suffered "long-term injuries" while on duty with England, Jose Mourinho has said.
Smalling, 27, withdrew from the England squad with an undisclosed injury and was later photographed wearing a leg brace.
Jones also pulled out of the England squad after damaging his toe in a training ground challenge with Smalling, meaning Eric Bailly and Marcos Rojo are likely to start in central defence against West Brom on Saturday.
United will also be without Zlatan Ibrahimovic, Ander Herrera and Paul Pogba for the Premier League clash but captain Wayne Rooney is available.
Ibrahimovic and Herrera serve domestic bans at Old Trafford on Saturday, while midfielder Pogba will be absent with a hamstring injury.
"The important ones are the ones who are ready to play," Mourinho said. "That's the way we have to think, we cannot be here crying or speaking about the players that are not available to play.
"You know about Zlatan and Herrera, they are suspended. You know that Herrera has two matches banned for that episode against Chelsea. You know what happened in the English national team with Smalling and Jones. You know that we have also Pogba injured.
"But I repeat they're not important. The important players are the ones that are ready to play, and the ones I trust, and the ones who are going to give everything tomorrow to try to keep us in the fight for the top four."
Antonio Valencia and Rojo both flew to South America for international duty but Mourinho said they are ready to play.
"They are not with injuries that stop them to play," he said. "Tired? Yes, of course but ready to try to help us."