Louis van Gaal hailed his "magnificent" players as he began his reign as Manchester United manager with a 7-0 rout over the Los Angeles Galaxy.

Wayne Rooney, Ashley Young and debutant Reece James all scored twice, and Danny Welbeck also found the net as United crushed the Galaxy in the Pasadena Rose Bowl.

Ander Herrera, also turning out for United for the first time, showed why the club paid £28million for his services.

The Spaniard put on a dynamic and destructive display, breaking up play and spraying killer passes across the park.

Van Gaal, who sent United out in the 3-5-2 system he used with Holland at the World Cup, said his new squad should take confidence from dishing out such a hiding.

"The result always matters. With such a result you get confidence," the new United boss said.

"It is fantastic how they have performed today. When you see us train, you can expect something but not 7-0. They were great goals."

Welbeck got United off to the perfect start with a 25-yard finish and Wayne Rooney made it 3-0

after a penalty and an easy tap-in.

James, one of nine half-time substitutes, tucked away two tidy finishes from inside the box and Young then rounded off the rout with two late goals.

Many had suggested Van Gaal did not have the strength in depth to send United out in a 3-5-2 formation, but he had no qualms about doing so in California.

The 62-year-old, who used the formation for most of his run to the World Cup last four in Brazil, deployed Luke Shaw and Antonio Valencia as wing-backs while

Jonny Evans, Chris Smalling and Phil Jones started at centre-half.

With Darren Fletcher captain for the night, United looked solid all evening. It was a surprise, therefore, to hear the squad had barely practised playing in that formation.

"We introduced a new system that we have only played two times on the training pitch 11 v 11," the former Barcelona manager said.

"But the boys are willing to pick up the information. Last week, 10 players who played tonight were not even in our training complex.

"When you want to change a system, you must start at once. The other system they can play is 4-3-3 and they have played it for many years.

"I can change back if the system doesn't work. With the quality of the players we have, I can play 4-3-3 with three strikers on the bench, but I want to play with two strikers."

lManchester City began their pre-season tour of America with a 4-1 victory over MLS champions Sporting Kansas City.