Herrera, signed from Athletic Bilbao for £28m, was imperious in his first outing as a United player and picked up the Man of the Match award as one of only two players to complete the full 90 minutes.
Mata, who played alongside Herrera in the first half, believes the 24-year-old will be a star at Old Trafford.
“He did great,” the Spaniard told ManUtd.com. “I know him very well from our days with the Spanish national youth team and he was very good tonight.
“I am very happy for him. We have a good connection on and off the pitch and I think he will give us a lot of good things this season.”
United fans will have been thrilled to see Herrera display the Paul Scholes-esque qualities that have been missing from United’s midfield for a few years. The Spaniard has the added ability to tackle though which he demonstrated when he nudged Robbie Keane off the ball before being hacked down.
Herrera’s performance typified a confident display from United in their first game under Louis van Gaal and Mata said the players had immediately taken to the manager’s system of play.
“We are all pleased with the result but we know this is just the first step,” he said.
“Some of the players have only been training for three or four days so we have more improvements to come, both physically and mentally.
“But I think we had a good understanding of the new system and the football the manager wanted us to play… the manager wants us to play quickly with the ball in the middle, try to look for options and also play with width as well. That’s what we’ll keep trying to do.”