Ole Gunnar Solskjaer suggested David de Gea was preparing a Manchester United counter-attack when he failed to gather Ismaila Sarr's looping shot.
"No, I've not asked him," Solskjaer said. "It's just a ball that slips through his hands, a routine save he [should] make, he might be thinking about where we're gonna go from then.
"One of the things we are looking for now is when he catches it we're gonna go forward quick and maybe it's down to the next action.
"For me, it's his first [mistake]. Last week was a free-kick, that's end of discussion, he gets elbow in his face, it's a refereeing mistake. David is confident, training well, no bother with him."