The Portuguese star has been chased by United all summer after his strong campaign.
Fernandes is valued at £63m, which so far the Red Devils have been unwilling to match.
But according to O Jogo, Sporting are still preparing for life without their goalscoring captain.
The newspaper claims that manager Marcel Keizer is resigned to losing Fernandes and has started looking at changing his formation in pre-season games to get used to playing without the attacker.
O Jogo writes that a move to United is ‘probable’ at this stage – despite both clubs still yet to agree a figure.
Sporting will continue to hold out for as much money as possible this summer.
But reports earlier this weekend suggested the European club were starting to panic that United were ready to let the deal fall through.
According to Correio de Manha on Friday, Sporting were preparing ‘Plan B.
This plan would have seen them bring in funds from other players instead.
Sporting were reportedly prepared to sell Wendel, Raphinha, Marcos Acuna and Bas Dost if they didn’t receive their €70m (£63m) for Fernandes.
It has been clear for some time that the Portuguese side were prepared to sell their captain this summer.
Speaking earlier this month, president Frederico Varandas explained the club were already eyeing replacements.
“What I know and the guarantee I can guarantee is that this Sporting will be ready to compete with our ambitions,” he said.
“Let’s be prepared for the new season.
“It’s important for new players to realise the global dimension of this club and feel the weight of the jersey they will wear.
“And this crowded stadium is proof that we have thousands of fans scattered throughout Europe and the world.”