But Mijatovic, who scored the winning goal in Madrid's 1998 Champions League final triumph over Juventus, told Marca: "Real should have won. They played well in the first half. United were lucky at the start.
"If the [Fabio] Coentrao ball had gone in... Real had more possession in the second half, but without much intent or ideas.
"Sometimes it's better to have the ball less and create more danger. It could still be anybody's. We shouldn't write Real off. They can win, of course they can win in Manchester."
Meanwhile, Mijatovic's ex-Madrid strike-partner Suker, believes there is still much to play for when the Liga holders travel to the Theatre of Dreams.
"I don't have any doubts [that Madrid will progress]. There is another game to be played. Real were strong in the first leg and got away without being beaten," the ex-Croatia forward added.
"But Real are capable of winning at Old Trafford. It is a good stadium to play and win at."