The combative frontman has been heavily linked with a move to London in recent weeks, as Chelsea seek to bolster their strikeforce ahead of the 2014-15 season.
Jose Mourinho's men fell four points shy of champions Manchester City last season, with the Portuguese complaining about his attacking options for much of the campaign.
Costa, who scored 36 goals in all competitions for Atletico Madrid in the 2013-14 campaign, is thought to be the solution to Chelsea's problems.
And the 25-year-old, currently out in Brazil for the FIFA World Cup with Spain, explained to Goal.com why he is keen to move to Stamford Bridge.
"Why would I have chosen to play for Chelsea?" he said. "It is a thing that is about to happen.
"Things are going in a direction and, if they keep going as they are going, it is the team I will play for in the next season.
"I've wanted to play in the Premier League for a while. I will have to work a lot to fit in with the style of the Premier League.
"Chelsea are one of the greatest clubs of the world so there are many factors that make you take a decision like this."
