Rooney struck twice in last night's Club World Cup semifinal against Gamba Osaka and said: "I think Wayne can be a number nine.
"We are trying to develop him that way. We have tried to play him there for most of the season.
"His movement, strength and penetration are very good. For the third goal that really killed them he made two runs, across and back and across and behind. They were really clever.
"It marks out the quality he can give you in that position and he will improve from there."