Ryan Giggs was critical of Anthony Martial's technique as the Frenchman attempted to pounce on an error by Ederson in Sunday's Manchester derby.
Martial opened the scoring for United with a 30th-minute volley that Ederson failed to keep out at his near post but he failed to capitalise on another mistake by the Brazilian after the break.
City's goalkeeper looked as though he had handed Martial a tap-in when he allowed a back-pass to slip underneath his foot, only to deny United's No.9 with a last-gasp challenge.
Ederson did eventually make another goal-costing error as Scott McTominay curled home from his misplaced roll-out in injury time to wrap up all three points for the hosts.
However, Giggs revisited Martial's failure to double his own personal tally for the day after the final whistle.
"It was echoes of David de Gea last week. He [Ederson] was dithering on the ball," Giggs told Premier League Productions.
"Martial and United pressed well at times. Me and Michael [Owen] were just talking about it and maybe I'm being overcritical but he should actually go with his right foot and block Ederson's attempt to clear it.
"But instead he goes with his left foot. He doesn't quite get there and clatters into the post. It's a strange technique really to go with his left foot rather than blocking it with his right foot."
Michael Owen added: "He goes for the ball as if the keeper isn't there to tap it in but he needs to use all weight and almost tackle the ball into the goal with momentum and weight.
"He was never going to score just by tapping it in because Ederson was always going to tackle him so right foot, all your weight behind it and tackle the goalkeeper. Put them both into the net."