Mount played nearly 200 games for Chelsea before switching to Manchester
The 24-year-old midfielder impressed on his first 45 minutes for the club, as they opened their pre-season with a 2-0 win over Leeds United in Oslo.
Mount, who signed from Chelsea for £55m, played the first half before 11 changes were made at the break.
"He will bring dynamism into our game and that was one of our conclusions last season," Ten Hag told MUTV.
"His vision is to play the offensive. But also he wants to be multi-functional, he wants to be complete.
"When you're playing in midfield, you have to attack, but you also you have to defend. We need to be more dynamic in the midfield department.
"I'm sure he will contribute to the success of United because he is a quality player."
Ten Hag's starting XI was a combination of youth and experience, with Lisandro Martinez, Raphael Varane and Jadon Sancho joined by young prospects such as Kobbie Mainoo and Omari Forson.
German manager Daniel Farke took charge of his first game in charge of Leeds, who are preparing for life back in the Championship following relegation last season.
But the breakthrough came on 67 minutes as 18-year-old Norwegian Isak Hansen-Aaroen played in Frenchman Noam Emeran who slid the opener past Dani van den Heuvel.
Emeran then turned provider for Joe Hugill to seal the win 10 minutes from time.
Mount created a big opening in the 10th minute, passing in behind for Amad Diallo to tee up Hannibal Mejbri but the Tunisian was denied by a smart save from Leeds goalkeeper Kristoffer Klaesson.
Moments later the England midfielder was involved again, winning the ball back before attempting a delicate chip over Klaesson from 25 yards which landed on the roof of the net.
"It felt great to be on the pitch," said Mount. "We have had that time in training and we have been working so hard, so it is great to show that in matches now. We have been working on a few different tactics," he said.
"I really liked the role I was in today. Being able to drop in and build up the play from a bit deeper, but with that license to go forwards and make runs into the box and be involved in more attacks.
"I like to start off the press, to give the opposition something to think about and then to combine that with an attacking threat and rhythm of our own."
Manchester United's pre-season continues with a match against Lyon in Edinburgh on Wednesday before they head to the United States for games against Arsenal, Wrexham, Real Madrid and Borussia Dortmund.
-- Courtesy of BBC Sport