According to Portuguese outlet O Jogo, Sporting want to get a deal done soon so that they can reinvest.
Their president has just returned from holiday and he reportedly wants to thrash out a deal.
Paul Pogba, meanwhile, has been linked to Real Madrid in what would be a big money move.
But Pogba's situation is not thought to have any sway on the move for Fernandes.
This is a contrast to Tottenham who are believed to be waiting until Christian Eriksen's future is settled.
Fernandes is wanted by many European clubs, including Inter Milan and Manchester City, but it is understood that United are leading the way.
With 32 goals from midfield last season, the 24-year-old would be an exciting adition to any side.
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