England captain and record goalscorer Rooney, 30, damaged knee ligaments during United’s 2-1 defeat at Sunderland earlier this month.
England play world champions Germany in a friendly in Berlin on March 26 before hosting Holland three days later as they build up to Euro 2016 and Van Gaal said that Rooney will not be available for selection.
“No, he won’t be ready for England next month,” Van Gaal told the Daily Star Sunday.
“Wayne has a brace fitted now and he has to wear it for two and a half weeks. After that we then have to look again.
“Now he’s resting and isn’t able to do any work yet. He has to be ready for us — not the English team.”