The England forward converted a seventh-minute penalty before adding another in the second half as United ran out 4-0 winners.
However, rather than be content with his brace, Rooney wants to improve on the rest of his game after describing his overall performance as "disappointing".
"It was nice to score two goals but I didn't think my performance was good enough," Rooney said.
"The rest of my play wasn't great. I am disappointed with that and I will be working hard to put it right."
Rooney passed the 30-goal milestone for the season with his double at Old Trafford on Sunday.