The Reds' number 10 played a key role in Saturday's dramatic comeback victory over Hannover 96, a game in which United's attacking prowess finally surfaced after a previously low-scoring DHL Tour.
"It was end to end at times," Rooney told MUTV. "We probably were a bit sloppy and could've done better defending, but I thought some of the play throughout the game was great, some great link-up play between us.
"Thankfully tonight we've got the four goals, which we've maybe been lacking in pre-season and it's great to get them in this game with the season coming up.
"[Pre-season] has been a bit stop-start with the international players coming back a bit later, but I think tonight you've seen the players are looking better every game, fitter every game. Hopefully by next Monday against Everton we'll all be ready. Obviously it will be a difficult game."
Having scored twice to haul United level in Germany, Rooney then teed up Shinji Kagawa to secure victory, and the England striker is impressed with how the Japanese international has slotted into the Reds' attack.
"It was great," said Rooney. "Obviously he's a very clever player and with the likes of myself, Chicharito, Tom (Cleverley)... there are players there who are capable of getting on the ball and linking the play and it worked for us tonight."