Newcastle manager Steve McClaren, making his first return to Old Trafford since coming back to English football, was impressed by how Steven Taylor and Fabricio Coloccini kept Rooney and his team-mates quiet.
"I think we did a very good job on him," said McClaren, who was assistant to Sir Alex Ferguson at Old Trafford for two-and-a-half years.
"We did a good job on (Adnan) Januzaj too. I thought the front four were excellent, we had to deal with that."
It was anticipated that Pedro would bolster United's forward ranks this week, but instead the former Barcelona forward joined Chelsea on Thursday.
One report claimed Van Gaal has now turned his attentions to Pedro's former Barcelona team-mate Neymar.
The Dutchman refused to discuss the report linking United with the Brazil star after the final whistle.
He said: "I don't enter in this discussions. You can ask about all the players in the world and you are doing that every press conference and I always say the same, I have to protect the interests of Manchester United, the players in my selection and the people in my organisation."
One of Van Gaal's former charges Krul also played a big part in the outcome of the match.
The Dutchman, who played under Van Gaal for the national side, saved from Rooney and Juan Mata before the break and at the death he pulled off a stunning save to deny substitute Javier Hernandez.!
McClaren was also impressed by the two centre-halves in front of his goalkeeper.
"I thought Coloccini and Taylor were excellent," the former England manager said.
"You have to defend well and they were immaculate, they kept us in the game the first 20 minutes and in the last 10 minutes.
"Colo was the leader out there, Taylor also."