Cristiano Ronaldo put Manchester giants City and United on red alert after admitting he wants to quit Real Madrid, according to a report.
If Ronaldo does return to Old Trafford, the Red Devils could have the deadliest strike force with Dutch star Robin van Persie and a certain Wayne Rooney waiting on the wings.
“Yes, Cristiano told president Florentino Perez he wants to leave the club,” The Sun reported the former United star as telling quoting unnamed sources.
Ronaldo sparked a storm of media speculation over his future on Monday by saying he was "sad" at the club.
“I am sad and the people at the club know about it," said the Portugal superstar who did not celebrate either of his two goals against Granada on on Sunday.
“It’s about professional issues. I can’t say any more,” he added.
Ronaldo was elusive about the reasons for his unhappiness, saying only that it was professional rather than personal. "I am not going to say more. People know why," he was quoted as saying in the media.
Asked if he was upset because Barcelona midfielder Andres Iniesta was crowned UEFA Best Player in Europe on Thursday, he replied: "No, it's not that. There are more important things."
Iniesta deserved the award, he added.
The 27-year-old Portuguese said his thigh was hurting but he hoped it would recover in the next few days to allow him to play.
"He can't take it any more," headlined the front page of top selling sports daily Marca.
Ronaldo "disconcerts Madrid and sounds alarm bells after not celebrating his goals against Granada," it said.
Ronaldo had gone to see Real Madrid chairman Florentino Perez on Saturday to say he was unhappy in the club, the paper said, without citing a source.
Marca said team-mates, who were not named, believed he had become more miserable since Iniesta was honoured. Ronaldo and Barcelona striker Lionel Messi had also been in the running.
"Does he want to go?" asked an article in rival sports paper AS. Ronaldo's "attitude is a depth charge that could explode with serious consequences if no-one intervenes urgently at the club."