Teenage debutant Rashford scored a brace and Dutch winger Depay capped a sparkling performance with a goal as United progressed to the Round of 16 in the Europa League.
"It's a great night for him and all the other youngsters in the squad," Blind said of 18-year-old Rashford, who scored two second-half goals on his senior debut.
"It's great to see them playing well. And I'm really pleased for Memphis too - he was brilliant."
United overcame a 2-1 first leg defeat and conceding a first-half goal to eventually beat the Danish champions 6-3 on aggregate.