Manchester City, Chelsea and Arsenal are all reportedly interested in the 23-year-old.
Nani said: “I know there are many rumours regarding Manchester United’s interest in Veloso but I can’t decide whether he comes.
“I know him well because he was a team-mate of mine and I know he has the quality to play for a club like United.
“The football here is hard but he is someone who can do well at a big club. And I know he already has the opportunities to leave Sporting.”