Douglas Costa was linked to Chelsea during the January transfer window, and on Tuesday, was linked to the Blues again. The Daily Mail are reporting that Jose Mourinho and company are keeping themselves up to date on a long standing knee issue, and if they're satisfied that the problem won't be a long-term concern, will push ahead for a move this summer:
Chelsea are being kept updated on Douglas Costa's fitness ahead of a £20 million summer swoop. The Brazil international is a long-term target of Jose Mourinho, who is keen to bring the Shakhtar Donestsk midfielder to Stamford Bridge.
And the Blues will revive their interest in the 24-year-old ahead of next season provided they receive assurances over a long-standing knee concern. Chelsea are being regularly updated on Costa's fitness and will press ahead with a move if they are satisfied with the joint in question.
I was very high on Costa 3-4 years ago when I watched Shakthar semi-regularly (I was actually higher on Costa than I was on Willian, who I also liked), but haven't followed the Ukrainian side very much since Willian's move to Russia. I suppose that's going to have to change over the next several weeks, as it doesn't look like the links to the player are going to end at any point in the near future.