Reports have claimed the Red Devils are among clubs keeping tabs on Mangala as they look to bolster their defensive options next season
Mangala switched to the Portuguese outfit from Standard Liege in 2011 and helped the club retain their title last season.
The 22-year-old, who has represented France at Under-21 level, is flattered by the speculation, but he acknowledged his current club would have a say in any potential transfer.
He told Sky Sports: "I am definitely flattered by the interest of such a big club like Manchester United, any player would be.
"I have a contract here until 2016 so even if I want to go, Porto will have their say in the transfer."