Nani believes the Premier League is set to be another two-horse race between Manchester United and Chelsea.
Chelsea looked to be in pole position to reclaim the title after a fine start to the season, but their form has since dropped off to allow the likes of United, Arsenal, Manchester City and Tottenham to enter the running.
However, Nani believes only United can provide a serious challenge to the champions this season.
"I no longer see anybody winning the Premier League this season outside of Manchester United or Chelsea," he said in The Sun. "Hopefully, it will be United."
Arsene Wenger has shrugged off those claims, and he believes Nani's comments should be taken with a pinch of salt.
"First of all I am surprised we have lost five games, three of them at home against teams who are not normally fighting for the championship," Wenger said in his press conference on Thursday. "The good news is we are in a strong position and we have not paid a high price for that. Our home form in the second half of the season will be a decider.
"Everybody has a different opinion in this league, but nobody is a prophet. We are in a society where everybody knows everything and it looks like it is a shame to say I don't know. I personally don't know who will win the league and I have managed 1,600 games. So if Nani knows, he must be 1,600 times more intelligent than I am."
Nani, whose form has improved since Cristiano Ronaldo left for Real Madrid in 2009, has revealed he is targeting a Ballon d'Or nomination next season.
"I know I can become a better player and my aim now is to get on the list of nominees for next year's Ballon d'Or," he said. "I want to leave my mark and hope after I retire that people will say Nani was a great player.
"I really want to do something special in my lifetime."
"It is easier for me to stand out now that Cristiano Ronaldo has left the club. He is a fantastic player who got all the attention and deservedly so. I loved playing alongside him and we got on well together but it is also true to say that, when he left United, it freed up space for other players to shine.
"When he left, I saw an opportunity to demonstrate my qualities and to show the people at United what I can do. That is exactly what I have done."
Nani credits Sir Alex Ferguson for the improvement in his form.
"Sir Alex Ferguson explained to me the importance of defending well and said I would end up being more dangerous in attack as a result. It is the truth."