Louis van Gaal has admitted he is not yet sure if Wayne Rooney can play as a No. 10 in his new system.
The Manchester United manager had planned to use his captain as his main striker this season, but new signing Anthony Martial has scored four goals in as many games to stake his case to lead the line.
While Van Gaal insisted he is unconcerned by the longest Premier League drought of Rooney's career, which encompasses 11 games and almost 1,000 minutes without a goal, he remains to be convinced that the 29-year-old can function successfully in a deeper role upfront with the £36 million 19-year-old.
"I have to wait and see if he can play as a second striker in this system, which we now play," the Dutchman said in a news conference.
"I think that Wayne can play a lot of positions. He has shown that last season. I want to play with a first striker and a second striker and maybe they are a very good duo together. We shall wait and see."
Van Gaal still intends to deploy Rooney as a No. 9 when his sidekick in attack is Marouane Fellaini, rather than Martial, explaining the need for pace in attack is why he has not allowed James Wilson to go out on loan.
"He [Rooney] is a striker for me and maybe I shall use him behind Martial, but when he plays with Fellaini, he shall always play in front of Fellaini because I want a striker who is running in behind," he explained.
"That's also why I want to keep Wilson until December maybe because he is also a typical striker running in behind."
Rooney has scored two goals for England this season as well as a Champions League hat trick against Club Brugge, and found the net in the Capital One Cup when United beat Ipswich 3-0 on Wednesday.
But while Van Gaal deflected questions if he still believes Rooney can score 25 goals this season, he shrugged off queries about his inability to strike against top-flight English opposition.
"Yeah, but I don't think that is an issue for him, for me or for the club so he shall score also in the Premier League," he said. "That I am convinced of. And you shall see it.
"Also he has been a little bit unlucky. I can give you an example: Against Newcastle [in August's 0-0 draw] he scored and it was not offside but it was cancelled. You cannot manage the referee. The referee is independent."