That is according to former France international and Red Devils striker Louis Saha.
Jose Mourinho’s men return to Europe’s top competition this week for the first time since being knocked out at the group stage in 2015.
United welcome Swiss outfit Basel to Old Trafford on the back of a 2-2 draw with Stoke City on Saturday.
The result ensured they remain unbeaten in the Premier League this season.
But according to Saha, domestic success shouldn’t be United’s sole focus this season.
“They can be a threat to Real Madrid for the Champions League trophy,” Saha told Starsport.
“They clearly have the talent, and the manager will have them working hard to be consistent and reach that type of level.
“He’s [Mourinho] proved over the years that he is capable of producing and getting his team winning trophies.”
United struggled domestically in Mourinho's first season despite winning two other trophies.
And Saha believes the 54-year-old is now better equipped to lead his team to glory.
“I think the environment at United last year was something new to him,” he added.
“But now he seems to be more in control of everything around him.”
Along with Basel, United play CSKA Moscow and Benfica.
Louis Saha has made the Big Call with online betting site BetStars. He is backing Real Madrid to win the Champions League. #Callit at https://www.betstars.uk/sites/football/championsleaguepreview/
