The 24-year-old is reportedly a target for Van Gaal, who coached the player during his time as boss of the Dutch national team.
This comes after another of the United manager’s reported targets, Thomas Vermaelen, joined Barcelona for £15m from Arsenal.
Blind revealed that he was happy at Ajax but admitted he had heard of the interest from the Red Devils.
“I am happy here in Amsterdam,” he said. “But if there comes another club I will have to think about it and then we will see.
“I will think about my options. For now I will focus on Ajax and we will see what happens next week.”
Ajax head coach Frank de Boer believes it may be too soon for Blind to make the move to the Premier League but understands why the player may end up leaving.
"I am convinced he will make the right choice," said De Boer. "If he goes to a big club then he has definitely deserved it.
"But I think it would be better if he stays one year. Last year was a good year for him but I think he can improve a lot with us.
"If a club comes along with a lot of money it is almost impossible to say no. But we won't let him go for free that is for sure.
"It is important for the player and the club that there is no tension or that it happens at the last minute."
Blind played 30 minutes of Ajax's opening day 4-1 Eredivisie win over Vitesse Arnhem on Sunday.
He was selected by Van Gaal in all seven of the Netherlands’ games at this summer’s World Cup in Brazil, operating as a wing-back in the new United boss’ favoured 3-5-2 formation.
He has made over 100 appearances for Ajax and would become United’s third major summer signing following defender Luke Shaw and midfielder Ander Herrera.