Barcelona head coach Ernesto Valverde refused to draw his gaze too far from Wednesday's Champions League Group D match against Juventus as speculation mounts over Lionel Messi's future.

Barca have gone 12 games unbeaten in LaLiga, sitting four points clear of Valencia at the summit, while a draw in Turin against the side who dumped them out of Europe's top competition last season would be enough to guarantee a spot in the knockout stages.

It amounts to a fine start to life as Barcelona boss for former Athletic Bilbao coach Valverde, but the contract status of talisman Messi continues to loom over the campaign.

The Catalan club announced in July that the 30-year-old had agreed a three-year contract extension until June 2021, which would be signed "in the coming weeks".

At least publicly, that has still not transpired and a palpable unease has gripped the Barcelona fanbase, with the prospect of Messi being able to negotiate a move away from Spain as early as January if he has not penned the extended terms a stark one to contemplate.

Barcelona president Josep Maria Bartomeu claimed on Monday that Messi had in fact signed three different deals - agreements with his Messi Foundation and one relating to image rights to run alongside the contract of employment - to cement his long-term future at Camp Nou.

It represents a saga that Valverde was unable or unwilling to shed further light on during his pre-match briefing at Juventus Stadium.

"I don't know how important the photo is [of Messi signing his contract]. He is with us, that's what we care about," he said.

"He travelled here with us and we're not going to think too much further beyond that.

"I don't want to start using bad language – we're going to have fun with what we're doing now and forget about all the back stories."

Barcelona have recovered impressively from Neymar's damaging defection to Paris Saint-Germain – a world-record transfer Bartomeu offered guarantees against happening – and midfielder Ivan Rakitic insists losing Messi is not an option.

"He has to be here, in my opinion, and I think he's going to be here for ever," said the Croatia international, speaking to reporters before his boss.

"He's part of the club. He's not just a very important part – it's more than that."

Rakitic is confident he will continue to share a dressing room with Messi but was unwilling to say so with absolute certainty.

"Looking at his career and how much it means for Barca, I can't say 100 per cent [he will stay]," he explained.

"We have to respect what everybody thinks. We know there are fans who want to see the picture, the handshake – I do too.

"I want to keep on playing with Leo tomorrow and three and five years into the future.

"All we can say as team-mates is we want him to stay with us and he has all our support. I think the journey still has a long way to go.

"I know from what people have told me that things are going well. I'm confident in Leo and our president. If we have to wait for a certain moment we have to wait. We are confident it will come."

Rakitic added: "Leo knows what's at stake. He knows we want him on our team. He's unique. I don't think you have to over analyse it, just relax.

"He's the most important player on our team. Everyone knows this and we have to give him all the support and love he deserves so he keeps coming out for us [to perform] every three or four days."