Darron Gibson says Manchester United teammates were unconcerned with Michael Carrick filling in at centre-half for the victory at West Ham.
With no Rio Ferdinand, Nemanja Vidic, John O'Shea or Jonny Evans, Carrick stepped into central defence and impressed.
Gibson said: "Michael did ever so well but I don't think Rio's got anything to worry about. The manager told Michael he might have to play centre-half if anything happened.
"It's unusual for us to be missing so many defenders but we've got so many players who can come and step in and give a performance and fill the gaps. The goal at the end of the first half gave us confidence when we went in at half-time."