Arsenal have a big problem on their hands - and his name is Laurent Koscielny.

A statement released by the Gunners on Thursday morning revealed their captain had refused to travel to the US for their pre-season tour.

It read: "Laurent Koscielny has refused to travel to the US for our pre-season tour. We are very disappointed by Laurent's actions, which are against our clear instructions.

"We hope to resolve this matter and will not be providing any further comment at this time."

Arsenal fans have since been wondering what could have happened behind the scenes for Koscielny to outright refuse to travel.

It's widely known that the 33-year-old would like to return to France one day, but he still has another year remaining on his contract and it's not in his nature to rebel.

So what's the situation? Well, according to the Mirror, it all stems from Koscielny being left "fuming" after holding transfer talks with Arsenal.

Koscielny reportedly wanted a 12-month extension on his current deal that would keep him in north London until 2021.

Arsenal were also keen to keep him, so they came back with an offer of a new two-year contract to be signed this summer.

But there's a catch.

Due to Koscielny's age and injury record, Arsenal's offer involved a lower basic salary than his current £120,000-per-week and included performance-related bonuses.

They also offered him the option to leave for free next summer and insisted his new contract could see him earn more if they qualified for the Champions League.

Koscielny, however, was having none of it and saw the new contract as having to take a pay-cut, which he isn't prepared to do.

Bordeaux are reportedly prepared to give Koscielny a three-year contract and it's understood that the Frenchman is set on returning to France.

Arsenal don't want him to leave for free and are making him train with the Under-23s in the meantime, but truth be told it's hard to see a way back now.