Antoine Griezmann
Griezmann\'s future continues to be the subject of intense speculation. Getty Images

Atletico Madrid are ready to increase the release clause of the much-coveted Antoine Griezmann to €100m (£75.6m, $109m) from his current €80m to ward off potential suitors ahead of the summer transfer window, according to AS. The Spanish publication claims that Chelsea, Real Madrid, Paris Saint-Germain and Bayern Munich are all interested in securing his services, but the France international is likely to stay at the Vicente Calderon for the long-term.

The 24-year-old forward has been linked with a move to the Premier League since his days as a promising starlet at Real Sociedad. His impressive development under Diego Simeone has increased those speculations with him becoming the spiritual leader of the Colchoneros, scoring 14 goals in 25 appearances this campaign.

The Spanish giants improved his contract last year with a pay rise and a new release clause of €80m. But the new deal has failed to ward off the big European clubs, with the Daily Mirror reporting that Jose Mourinho had identified the player as his prime January target if he had stayed at Chelsea. Manchester City were also believed to be in the mix.

Atletico Madrid president Enrique Cerezo played down these speculations last month, claiming: "Players play where they want to play. Right now, Griezman's thoughts are not on a sheik or blue princess coming to sign him.

"His thoughts are at Atletico Madrid, he wants to be at Atletico Madrid. He proved this by signing a renewal recently."

But AS claims that the club are "concerned" over Europe's big-spenders coming for the Frenchman, and are ready to offer him a new deal that will see his salary increase while raising his release clause to €100m.

The Spanish publication claims that Chelsea, Real Madrid, Paris Saint-Germain and Bayern Munich are all monitoring the situation, with the Blues expected to make a major squad overhaul in the summer.

The La Liga side have seen a number of players, like Diego Costa, Sergio Aguero and Radamel Falcao, leave the club in recent seasons. However, since Simeone kickstarted a new era of success at the Vicente Calderon they are determined to keep their major assets to continue the fight with Barcelona and Real Madrid for the titles.

The report from AS came just before the club, alongside Real, were been banned by Fifa from all transfer activity for the next two transfer windows, owing to irregularities regarding the signing of underage players. This makes the retention of Griezmann even more vital, as if the ban is effective they will be unable to sign a suitable replacement.