Diego Costa
Diego Costa has been impressing this season for Atletico Madrid. [Reuters]

Reported Arsenal and Manchester United target Diego Costa is not thinking of leaving Atletico Madrid this January, according to the club's sporting director.

The 25-year-old's relentless form in front of goal has been one of the key factors behind Atletico's incredible first half of the season where they are on course to break Real Madrid and Barcelona's stranglehold on the league.

Both United and Arsenal have been linked with bids for Spain's top scorer this season with reports suggesting the Brazilian born forward was the focus of attention when David Moyes travelled to the Vicente Calderon to attend a Champions League game earlier this month.

But Atletico's sporting director Jose Luis Caminero is unconcerned by reports suggesting the Premier League giants are plotting a bid and is confident Costa does not want to leave the Spanish capital.

"Right now Costa does not think of leaving, he is contracted to Atletico," Caminero told La Marca.

"He has renewed with us which is important. He has shown that he wants to continue at this club."

Costa, who has struck 19 goals in 20 games this season, has already demonstrated his loyalty to Diego Simeone's side. Liverpool met the striker's buyout clause during the summer as Brendan Rodgers tried to pair him with Luis Suarez in what would have been a fearsome attack.

Costa however turned down Liverpool and signed a new contract with Atletico which keeps him at the club until June 2018, and his manager believes there is plenty more to come.

"He himself has his own limit," Simeone told AS. "He should never forget what it has taken to be such a player with so much personality and balance.

"If he doesn't forget this, with all the effort he has put in so far he will continue to grow. We are all convinced that he is a player who can grow a lot."