Fernandes has been linked to United throughout the transfer window and talk of a switch to Old Trafford has gathered pace with the Premier League season on the horizon.
Sporting president Frederico Varandas has already warned potential suitors the Portugal international will cost more than €62million.
Fernandes did not give much away when asked about his future amid growing links to United.
"I don't care about the transfer market. I've talked about this a lot, I don't need to talk anymore. I already said I would like to play in England," the 24 year-old midfielder said. "When the club decides [is when it will happen]. I'm not in charge."
When asked whether United is a potential destination, Fernandes replied: "I'm not the one to decide. I am not the president of Sporting."
Sporting will face Champions League holder Liverpool in a pre-season friendly in New York on Thursday (AEST).
On whether it could be his final match for the team, Fernandes added: "It is the coach who decides if it will be the last."
Fernandes scored 20 goals – 31 in all competitions – and supplied 13 assists in the Primeira Liga last season as Sporting finished third.