Ferguson explained his decision to select Anders Lindegaard for his Premier League debut in preference to normal goalkeeper David De Gea.
"It was an opportunity to play Anders," said Ferguson.
"He is going away with Denmark this week but probably won't play, whereas David is likely to play twice for Spain's Under-21 team."
With England's crucial Euro 2012 qualifier with Montenegro looming on Friday, Fabio Capello will have noted Wayne Rooney's return from a minor hamstring strain and Ferguson confirmed Ashley Young will also be available for the trip to Podgorica.
"Ashley has got an ankle knock," said Ferguson.
"It wasn't worth the risk with him but he should be OK for England."