The Japan international, who joined from Borussia Dortmund earlier this summer, has been impressive during pre-season and Rooney is excited about having the attacking midfielder in the Red Devils line-up.
"Shinji's settled quite quickly. He's a talented player, he likes to get on the ball and keep it simple. He's very effective on the ball," Rooney said.
"It's great to have that sort of player in the team. I'm looking forward to playing with him and I think he'll create a lot of chances for myself and the other forwards. It's exciting to have him in the team."