"The player has a clause of 38 million euros and the big clubs in England know this," Caminero is quoted by Marca.
"Diego Costa has matured and is smart when it comes to decision making.
"Right now, Costa does not think of leaving, he is hooked on Atletico. He has re-signed a deal that is important, I am confident he will continue with us."
Recent weeks have also suggested that United are preparing a move for their 21 year old midfield starlet Koke.
"I'm not surprised with this subject," Caminero responded, when asked about United's interest.
"He is a player who has improved considerably. It has also made it into the Spain squad and that puts you in the spotlight and opens more eyes.
"Koke will be with us for many years. I am convinced," he concluded.
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