The transfer window is closed until January but that doesn’t keep the rumour mill churning as clubs look to get a leg up on potential transfers.

Here are three big stories dominating the headlines on Sunday.

Will any of the following deals happen?

Let us know your thoughts via Twitter and Facebook.

CHELSEA IN THE HUNT FOR GREMIO STAR

Chelsea could be set to hijack Barcelona‘s pursuit of Brazilian youngster Arthur, according to reports.

The Gremio prodigy, who is missing the ongoing Club World Cup in the UAE due to injury, is touted as one of South American football’s hottest talents and is attracting big interest.

After helping the Brazilian side to their first Copa Libertadores trophy since 1995 last month, Arthur met with Barcelona sporting director Robert Fernandez and other representatives in Porto Alegre – sparking rumours he was close to finalising a January switch to the Camp Nou.

Indeed, he was even pictured in a Barca jersey.

However, the player has since come out and said that he will not leave his boyhood team behind their back – putting the brakes on any imminent transfer.

That might be just as well for Chelsea, giving the Premier League club more time to muster up a package to tempt the midfielder to west London.

RATING: 8/10

VERDICT:

The 21-year-old could well become a star at next summer’s World Cup in Russia and Chelsea are more than ready to battle for his services, according to the Mirror.

Given Barca have done much of the early running in this deal, don’t expect Blaugrana to let the English side un-do all of their hard work.

Ernesto Valverde’s men are most likely to set about tying up a pre-contract agreement ahead of a transfer at the end of the season.

The next Andres Iniesta? Arthur is a fine prospect.

VALVERDE IN NO RUSH TO LET JAVIER MASCHERANO LEAVE

Barcelona boss Ernesto Valverde has made it clear he will not be weakening his squad during the upcoming transfer window – possibly giving a hint that Javier Mascherano will stay until the end of the season.

The Argentine stalwart, who has spent seven successful years at the Camp Nou, is widely expected to seek a fresh challenge in 2018 with a move to China or return to his homeland both on the cards.

But, as Barcelona fight for silverware on both domestic and European fronts this term, Valverde feels he needs to call upon all the resources in his squad – and is not prepared to allow players to leave if significant re-strengthening has not been completed.

“Our intention is to become stronger, not weaker,” he said ahead of Barca’s must-win clash at Villarreal on Sunday.

“The window hasn’t yet arrived; it’s true there are issues emerging that must be dealt with.

“Mascherano is with us and whenever he has played, he’s done well, if he leaves we will consider alternatives.”

RATING: 7/10

VERDICT:

It is clear this will be the former Liverpool midfielder-turned-defender’s last season in Catalonia but Barca may feel it is worth keeping hold of his experience for the remainder of the campaign.

Mascherano’s professionalism and respect he commands at the club is an asset – plus Barca are under no financial pressure to sell. Expect speculation concerning the 33-year-old’s future to run and run, but also expect him to stay put for now.

Valverde went on record about the club veteran.

JESUS VALLEJO IMPRESSES ZINEDINE ZIDANE WITH SOLID DISPLAY

The Spaniard put in a terrific performance at the heart of the Los Blancos defence as Real Madrid ramped up the pressure on Barcelona with a 5-0 rout over Sevilla.

In the absence of both Raphael Varane and Sergio Ramos, Vallejo did what was asked of him and showed total commitment – impressive, given he had missed the mid-week Champions League clash against Borussia Dortmund due to injury.

The 20-year-old, who signed for the Spanish giants from Real Zaragoza back in 2015 but was immediately loaned back and then spent last season out on loan at Eintracht Frankfurt, had initially failed to convince Zinedine Zidane he was good enough.

But, that perception seems to have changed now, with Vallejo looking like he could become a solid first-team back-up and eventually starter for the whites.

It all but puts an end to speculation linking him with a move away from the club in January.

RATING: 7/10

VERDICT:

While the youngster still has work to do to consolidate his spot in the Real first-team, he has at last shown signs he is up to the task of wearing the famous Whites jersey.

That means he’ll be at Madrid for a while yet.

Solid as a rock: Vallejo.