Manchester United manager David Moyes felt his side "could not have been more unlucky" in a 2-1 defeat at Stoke, their eighth league loss of the season.
Charlie Adam put the hosts ahead with a deflected free-kick and scored a superb winner after Robin van Persie levelled.
"I don't know what we have to do to win," Moyes said after the game. "I thought we were extremely unlucky.
"We played well but for their first goal it was an incredible deflection and the second was a worldy."
New £37m signing Juan Mata, Van Persie and Rooney started together in United's attack for the first time.
Van Persie briefly brought the Red Devils level with a clipped finish but, otherwise, they could not turn their promising build-up play into clear-cut chances.
United piled on the pressure late in the game but the closest they came to rescuing a draw was when Potters keeper Asmir Begovic kept out Rooney's injury-time free-kick with a flying save.
"We made numerous chances and opportunities to score, but we couldn't take them," Moyes added.
"Yes, Wayne went close but we also got to the byeline and cut things back three or four times without getting on the end of it, or picking anyone out in the box.
"We should have been out of sight with the amount of opportunities we had today and we only have ourselves to blame."
United remain seventh in the table, 13 points behind leaders Manchester City, who play third-placed Chelsea on Monday.
They are also six points behind fourth-placed Liverpool, who take on West Brom on Sunday.