Transfer Rater: Marcelo Brozovic to Man United, Coutinho to Barcelona

Things change in the blink of an eye in football. The Football Whispers Index takes the latest transfer rumours and gives them a score out of five; the higher the score, the more realistic and reliable the whisper.

Here are today's top five emerging whispers for the summer. And keep an eye on Transfer Talk for all the latest gossip.

Marcelo Brozovic to Manchester United

Manchester United are planning to trigger Brozovic's £43 million release clause this summer.

According to The Sun, Jose Mourinho -- who was spotted in Zagreb during the international break -- wasn't only there to discuss a move for Inter Milan forward Ivan Perisic, but also to enquire into the availability of his teammate Brozovic. The Croatian international midfielder has three goals and two assists for the Nerazzurri so far this season.

Calciomercato also believe the 24-year-old could be heading for the San Siro exit door, with the Serie A side thought to be in need of offloading players to comply with UEFA's financial fair play rules.

Philippe Coutinho to Barcelona

Barcelona continue to be linked with Liverpool playmaker Coutinho, with Neymar urging his club to make a move for his compatriot at the end of the season.

"I would sign Philippe Coutinho. He's a player that I see playing at Barca," the Brazilian star told Mundo Deportivo.

Reports from Spain have suggested Barca will use Ivan Rakitic as part of a player-plus-cash deal in a bid to tempt the Anfield club to part company with the 24-year-old.

Leon Goretzka to Tottenham

Mauricio Pochettino has identified Schalke 04's Goretzka as a transfer target for this summer, according to reports.

The 22-year-old Germany international has six goals for Schalke this season, but has yet to extend a deal that ends at the end of next season. Tottenham's chances of signing the player will be enhanced should the Bundesliga side fail to qualify for European football.

Markus Weinzierl's side currently sit ninth in the Bundesliga, four points outside of the Europa League places -- although they are in the quarterfinals of the competition this season.

Samu Castillejo to Arsenal

Arsenal, along with a number of Premier League rivals, are tracking the situation of Villarreal's 22-year-old winger Castillejo, according to Italian daily Il Mattino.

Castillejo has two goals and three assists in La Liga for the Yellow Submarine so far this season, and has made 37 appearances in all competitions, while his impressive performances have attracted the attention of Arsene Wenger.

However, Manchester United and Manchester City, as well as Napoli, are also keen on the Spain youth international.

Harry Maguire to Everton

Hull City's Maguire has emerged as a target for Everton as Ronald Koeman looks to bolster his defensive options, the Daily Mail are reporting.

Both Ramiro Funes Mori and Seamus Coleman are long-term injury absentees, while Phil Jagielka is expected to leave the club in the summer.

Despite the Tigers conceding 58 goals in the league so far this term, the 24-year-old former Sheffield United man has impressed for Marco Silva's side, with both Middlesbrough and Southampton also keeping tabs on the player.