Spain edged past brave Iran on Wednesday in Group B of the 2018 World Cup.
"I think we controlled the match [against Iran], but it is true they generated danger with the play of the disallowed goal and a header at the far post," Barcelona left-back Alba told Marca.
"In that respect I can understand how those doubts that are so much talked about are generated. Honestly, inside the dressing room we did not see it that way. But all opinions are respectable," he added.
"Portugal came to us three times: a dubious penalty, a foul that Cristiano put away incredibly and a mistake [by goalkeeper David de Gea]," he added.
"We were totally superior to Portugal and we deserved much more than them. But this is a World Cup. People may think that Iran is not at that level, but it made life more complicated for us than Portugal.
"We have four points, which is the important thing we have to look at. You always have to correct things, but this is a World Cup and we are seeing what happens every day in almost every game," Alba concluded.