The Swedish international was linked with the Red Devils back in January but a move never materialised.
In recent days, however, Portuguese paper Record reported that a summer deal has been struck. The news outlet claimed Lindelof would be following Ederson Moraes to the Premier League, after the goalkeeper agreed a deal with rivals Manchester City.
The 22-year-old made 46 appearances this season and helped guide Benfica to a league and cup double.
However, the defender, who is currently on international duty with Sweden, has rubbished rumours of any done deal.
“I have my contract with Benfica and I am happy there,” said Lindelof. “I will always say that. People can write what they want, I can’t do anything about that.”
Despite Lindelof rubbishing claims of a deal being done, Mourinho has refused to rule out a move for the defender.
He said: “I will not say if I want him or not, I don’t think it’s right.
“Rui [Vitoria, Benfica’s manager] is not going to be happy with another club manager talking about a player who is his, the president would not be happy to see that.
“Lindelof is theirs and as long as he’s theirs, he’s theirs.”