Atletico Madrid boss Diego Simeone has claimed that he is "fully responsible" for Jackson Martinez's struggles in Spain.

Martinez joined Atletico from Porto last summer, but struggled to make his mark at the Vicente Calderon and left for Chinese club Guangzhou Evergrande in the January transfer window.

Simeone has insisted that he is to blame for the striker's lack of form and that the pair parted on good terms.

"Jackson worked with enthusiasm and excitement, but after we spoke, we decided a move was best for both parties. He made an effort to engage and compete. Now we wish him well and hopefully he does well," Simeone told reporters.

"When a player doesn't respond [to my methods], I'm fully responsible. He didn't have the luck or chance to give his best here, so obviously I feel responsible. It's a failure of mine that Jackson is no longer here. It's a part of football, but I won't change my approach."

Atletico president Enrique Cerezo has claimed that Martinez 'did not rise to the circumstances' during his time in Madrid.