Chelsea's Douglas Costa transfer chase back on as they plan £20m bid for Shakhtar star

Blues almost signed the midfielder in the winter window and are ready to try again as they strengthen title-bound squad that fell short in Europe

Jose Mourinho will relaunch his attempts to sign Brazilian midfielder Douglas Costa with a £20million bid.

Chelsea boss Mourinho was keen in January and is ready to revive his interest in the summer - as long as there are assurances over the Shakhtar Donetsk star Costa's fitness.

Shakhtar are ready to cash in on their prize asset.

Real Madrid and Barcelona are also interested, while Manchester United, Arsenal and Liverpool have all made enquiries, but Chelsea are in pole position after having lengthy discussions about a move in the last window.

Mourinho is a big admirer of the 24-year-old but while Chelsea signed Juan Cuadrado from Fiorentina in the winter window, they could not get the Costa deal done in time.

Their interest is still there and they are back in the hunt for Costa, who is keen on a move to the Premier League with a Champions League club.

The league-leading Blues are keen to shake up the squad after this season's faailure at the last-16 stage of the Champions League, with Real Madrid's Raphael Varane their No1 defensive target.

Costa is also very much in their sights and these regular fitness checks show they are keen to finally get the transfer done this summer.

Gaining a work permit will not be an issue as Costa has dual Brazilian/Portuguese nationality.