The veteran was rewarded for his fine form in United colours this season with a place in Roy Hodgson's national squad for the concluding Euro 2016 qualifiers against Estonia and Lithuania.
Carrick is expected to return against Arsenal in the Premier League on Saturday after sitting out the team's midweek encounter against Wolfsburg, and Van Gaal has assured that the 34-year-old is nearing peak fitness.
"He [Carrick] is a quality player and I am very happy for him when Hodgson thinks he needs him because he wants to play for the national team," Van Gaal told reporters.
"I'm very happy for [Carrick] because he is also able to play for me against Arsenal.
"He was not injured, I have said that already. It was a minor injury and tiredness.
"He is 34 years old so it is logical that he needs more time to recover as a player but I am very happy with him."
Van Gaal is hopeful that Phil Jones can build towards match fitness during his time away with England.
"He has also selected Jones and he still needs minutes so I am happy that he can do that for the English squad, maybe," the former Netherlands coach added.
"It is always an honour to play for your national team and me, as a former national coach, I am aware of that.
"It is good that you are also in other environments to play - it can sort of relax for your mind."