Diego Costa is struggling to make an impact for Chelsea this season after a remarkable debut year with the Blues in 2015. His current situation at Stamford Bridge fueled speculation that the striker wants to leave the club.

Sources told ESPN FC that Costa wants to bolt out of Chelsea this summer amid reports that his former club, Atletico Madrid, is willing to spend and offer a lucrative deal once he becomes available.

Costa moved to Chelsea before the 2014-15 season and immediately made an impact at Stamford Bridge. The Brazil native netted 20 goals to go along with three assists in 26 appearances for the Blues last season, helping the club win the Premier League title.

However, the 27-year-old striker is not even close to equaling his numbers this year. Costa has only netted 11 goals on top of five assists in 24 Premier League matches this season. The ESPN source said that the Spain international has "struggled to settle in London" and he was irked after the club shopped for strikers last summer.

Chelsea could make big moves this summer after failing to defend their title in the Premier League and Costa could be one of the players to be let go after being involved in an ugly incident. The FA suspended Costa for misconduct after tackling Gareth Barry during their FA Cup match against Everton on Saturday.

While Costa has been a shadow of his old self this year, Atletico Madrid appear to be interested in taking him back, as they are expected to look for a striker this summer after moving Jackson Martinez to Guangzhou Evergrande.

Costa has also hinted that he is open to returning to the Spanish La Liga club, citing the case of Filipe Luis, who also moved to Chelsea in 2014 before returning to Atletico Madrid last summer.

"You never know, look where Filipe Luis is now," Costa told Onda Cero via ESPN FC. "Life takes plenty of twists and turns -- I always wish Atletico the best and I always follow them, support them from afar."

Atletico Madrid are expected to have sense of urgency when the summer transfer window opens, knowing that they could be disallowed to make transfers after being banned by FIFA. The suspension was temporarily lifted, giving them a chance to tweak their roster at least for the next transfer window.