With news Kalidou Koulibaly is on Tottenham's shopping list and a new Man Utd target, here's Sunday's back pages from Europe.
As a result, the rumour mill never stops. So we asked our friends at Football Whispers to round up all the latest news, views and gossip from across the continent.
Spain
After the arrival of Jose Mourinho, Tottenham have opened talks with Napoli over a deal for centre-back Kalidou Koulibaly. Spurs need to overhaul their defence with Toby Alderweireld and Jan Vertonghen out of contract next summer. (El Desmarque)
Valencia are the latest club to show interest in Atalanta United star Ezequiel Barco. The Argentine has also been linked with Arsenal, Manchester United, Inter Milan, Roma and Lille. (Sport)
Barcelona midfielder Carles Alena has not ruled out leaving Barcelona on loan in January. "The decision will be totally mine," he said. "I have a great relationship with the leaders and I'm sure they will let me choose what suits me best." (Sport)
Italy
Sergej Milinkovic-Savic will not rule out a move away from the Serie A side after scouts from Manchester United watched him score in Lazio's 3-1 win over Juventus. He said: "At the moment I am at Lazio. In the future, you never know." (Gazzetta dello Sport)
Juventus are prepared to offer Barcelona Emre Can in exchange for Ivan Rakitic in January. Both players have struggled for regular first-team football at their clubs this season. (Gazzetta dello Sport)
Lautaro Martinez does not plan to leave Inter Milan for Barcelona despite the La Liga club making the Argentine forward a priority target ahead of next summer. (Sport Italia)
Napoli president Aurelio De Laurentiis will attempt to re-sign Edinson Cavani at the end of the season when the Uruguay striker's contract with Paris Saint-Germain expires. (Il Mattino)
France
Nice manager Patrick Vieira has played down speculation he could take over at Arsenal. "I could never be insensitive towards a club where we spent nine years. But I am focused on this project at Nice, I feel very good here." (Canal+)
Lionel Messi has revealed he voted for Liverpool star Sadio Mane to win the 2019 FIFA Best Player Award earlier this year. "There are many great players and it is difficult to choose," the Argentine said. "But I selected Mane as he is a player I love to watch." (Canal+)
Germany
Joshua Kimmich has warned his Bayern Munich team-mates they risk losing their grip on the Bundesliga title if they do not improve. "Anyone who has not grasped it yet is completely on the wrong track. If they believe it will be the same as last season, they are out of place." (Kicker)