Rooney was encouraged by the attacking interplay that produced more goals in one night than the team had managed in the previous five games put together.
"It was end-to-end and we were a bit sloppy at times. We could have done better defending," the 26-year-old forward told MUTV.
"But I thought some of the play throughout the game was great. Some great link-up play between us.
"We've got the four goals which maybe we were lacking in pre-season and it's great to get them with the season coming up."