The football world's gossip mill is in full swing, and Transfer Talk is monitoring the whispers ahead of all the summer moves. Check out the latest deals and potential deals here.

Costa signs pre-contract for China move

Diego Costa was spotted having dinner last Friday in London with agent Jorge Mendes and four others, and Cadena Ser has the skinny on the topic of conversation at the supper party.

The outlet reported that the men were representatives of Tianjin Quanjian and that Costa has signed a pre-contract to move to the Chinese Super League in a deal that will see the Spain international earn €30 million per year to play alongside Alexandre Pato and Axel Witsel.

Chelsea are apparently well aware of the deal, which will be finalised at some point in May, and will use the reported €90 million transfer fee to sign one of Antonio Conte's top summer targets, Real Madrid's Alvaro Morata.

Man United see Mbappe bid knocked back

Manchester United have been turned away by Monaco after bidding £72 million for Kylian Mbappe, the Guardian reported.

The Red Devils have moved for the 18-year-old sensation but have been firmly told by the Ligue 1 leaders that the player's value is not negotiable and that Mbappe will cost £100 million.

The France international failed to score against the steely Juventus defence in the first leg of the Champions League semifinal, though that was in no small way due to the stellar play of Gigi Buffon in goal.

Monaco are in no rush to sell, with a plan to hold tight and cash in for £125 million in 2018, with the club knowing full well that Mbappe's dream is to join Real Madrid.

The outlet also reported that Mbappe isn't Jose Mourinho's only high-profile target this summer, with the United manager assembling a list of potential midfielders for United to target this summer. Toni Kroos, Radja Nainggolan and Tiemoue Bakayoko are thought to be high on United's wish list.

With Morgan Schneiderlin sold to Everton in January and Michael Carrick nearing the end of his career, Mourinho has identified this area as a priority to better challenge for the title next season.

Bertrand has Chelsea and Liverpool on alert

Ryan Bertrand has told Southampton he wants to leave, the Mirror reported, with Chelsea and Liverpool emerging as potential buyers.

The England international's career took off after he left the Blues, but he has reportedly told teammates of his desire to move on this summer.

Chelsea could be tempted to bring the 27-year-old home, while the Reds are desperate to upgrade at left-back, with James Milner only a temporary, out-of-position solution.

Milan line up star duo to kick off new era

AC Milan have moved closer to agreeing to two deals to ensure the new era under Chinese ownership begins with a bang, Tuttosport reported.

The Rossoneri completed a protracted takeover last month and a move for Villarreal defender Mateo Musacchio, with a £15.2 million fee agreed, looks set to go ahead.

Roma and Chelsea have made moves for Atalanta starlet Franck Kessie, but it's AC Milan that have moved into pole position for the talented, young, Ivorian centre-midfielder.

Tap-ins

-- Chelsea winger Willian is set for a Stamford Bridge exit this summer, the Star claimed, with the Brazilian rumoured to be a Manchester United target.

The Blues star struggled to hold down a starting spot, despite picking up last season's Player of the Year award, as Pedro has displayed fine form with more goals than his 28-year-old teammate.

-- Manchester City forward Nolito is eyeing a La Liga return this summer after failing to impress Pep Guardiola, the Mirror reported.

The former Celta star has started just 16 times this season and could look to move in a bid to secure a place in the Spain squad for the World Cup.

-- Atalanta have announced the signing of former Cardiff flop Andreas Cornelius from FC Copenhagen for around €3.5 million.

The 24-year-old once cost £7.5million for the Blue Birds but failed to settle, though 18 goals this season have convinced La Dea to give him another chance in a top league.