In a surprise development, United sources claimed last night that the club made a bid to sign Mane last week.
Southampton deny any offer has been submitted for the Senegalese winger, but a spokesman for the south-coast club said Mane is “not for sale” anyway.
Despite making five signings this summer, United manager Louis van Gaal believes his squad lack pace and creativity, and Mane certainly has both those qualities in abundance.
In his first year at Saints he scored 10 goals in 32 appearances, including the fastest hat-trick in Premier League history in the 6-1 win over Aston Villa.
The move for the player still comes as something of a surprise, however.
United were reported to be close to the capture of Barcelona forward Pedro last week, but it emerged yesterday the club had pulled out of the running to sign the 28-year-old.
Pedro now looks set to move to Chelsea instead.
Elsewhere, Newcastle have signed Marseille winger Florian Thauvin on a five-year contract.
The 22-year-old Frenchman came through a medical yesterday and committed to the club until 2020.
As part of the deal to bring Thauvin to St James’ Park, Remy Cabella heads the other way on a season-long loan, which will become a permanent move next summer.
“I am delighted to be a Newcastle United player,” said Thauvin. “I have come from France to a really big club and am very happy to be here.”
Thauvin was identified as a potential signing by chief scout Graham Carr more than two years ago and the club has been monitoring his situation since.
And boss Steve McClaren was happy the club have finally got their man.
He said: “Florian is a player the club have been watching for a long time and I am delighted we have been able to sign him. He is a perfect signing for this club — someone who is young, with great potential and is one of the best young players in Europe.”
West Ham co-owner David Sullivan says a deal has been agreed to sign Alex Song from Barcelona, if the midfielder can pass a medical.
The Cameroon international spent last season on loan with the Hammers and impressed sufficiently to earn a permanent move and a three-year contract, as long as the former Arsenal midfielder can prove his fitness.
Sullivan said: “We have a deal in place with Alex Song subject to a medical. If the medical is okay, we’ll take him. He’s a player we all admire and we just hope that the medical shows he’s in a sufficient state for us to gamble.
“He couldn’t physically pass a medical tomorrow, but if the medics say it’s just a technical thing and he’s only a couple of weeks away you’d take that gamble.”
Leicester are set to complete the signing of Gokhan Inler today.
The midfielder has completed a medical and agreed personal terms with the Foxes ahead of his switch from Napoli.
Boss Claudio Ranieri has been chasing a new midfielder after failing to persuade Esteban Cambiasso to stay after his contract expired this summer and he signed for Olympiakos this month.
He has already signed N’Golo Kante from Caen to beef up his midfield options but Inler is expected to join the club ahead of Saturday’s Premier League visit of Tottenham.
Wolves have insisted Benik Afobe is not for sale after he was linked with Norwich.
The club issued a strongly-worded statement to reiterate the striker will be staying at Molineux beyond the transfer window.
While the club did not address the Canaries link directly they insisted their prized asset will not leave.
Further afield, Real Madrid have completed the transfer of Mateo Kovacic and the Croatia international is thrilled to have joined “the best club in the world.”
The 21-year-old midfielder was unveiled to the media at the Santiago Bernabeu stadium after passing a medical and putting pen to paper on a six-year contract with the Spanish giants.
“Real Madrid is the biggest club in the world, I have no doubt about it,” Kovacic said. “This opportunity only comes once in a lifetime.”