Foster made at least four top-class saves during the 2-1 reverse.
Gracia said: “It's not a surprise to me. He usually does it in all the games.
“I think he played at the same level as the rest of the players because all of the team, in my opinion, are doing very demanding defensive work in the first half and in the second in the moment when we are tired we need to press a little bit higher, with long distances in the last minutes make an extra effort.
"I think we have played well knowing that playing against City is always very demanding."