Douglas Costa
Douglas Costa (centre) has been in fine form for Shakhtar Donetsk this seasonReuters

Chelsea are reportedly looking to reignite their interest in Shakhtar Donetsk star Douglas Costa with a £20 million bid.

The Blues had tried to sign the 24-year-old in January, but their bid of £16 million bid was rejected by Shakhtar.

There were reports of the Blues readying an increased offer of £18.7 million for the Brazilian, but the deal never finalised and Chelsea ended up signing Fiorentina's Juan Cuadrado instead.

However, according to the Daily Mirror, Chelsea boss Jose Mourinho, who is a big admirer of Costa, has still not given up his hopes of signing the Brazilian and is looking to land him in the summer.

Although the likes of Real Madrid, Barcelona, Manchester United, Arsenal and Liverpool have also reportedly made enquires about Costa's availability in the summer, it is believed that Chelsea are leading the race to sign him due to the Blues holding lengthy talks with Donetsk over the 24-year-old's transfer in January.

Also, the midfielder had earlier expressed his desire of working under Mourinho, whom he considers very "intelligent" and "victorious."

"To play at Chelsea is a dream for any player," he had earlier told "It is standing next to some of the best players in the world and competing with the world's best as well.

"But really, what catches my eye is the coach. He [Mourinho] is a very intelligent coach and has been victorious wherever he went. One of the things that would make me happier to play at Chelsea would be this."

Meanwhile, Chelsea are also reportedly readying a £40million to land Real Madrid defender Raphael Varane in the upcoming transfer window.

Mourinho, who has a very high opinion of Varane, having worked with the defender when he was the manger of Real Madrid, is believed to be very keen on bringing the Frenchman to Stamford Bridge as he looks to further reinforce the Blues' backline in the summer.

And the Sun claims that Chelsea chiefs have granted Mourinho the finances to make a £40 million bid for the defender in the summer.

Varane is also believed to be keen on leaving Real Madrid due to him being restricted to a bench role at the Bernabeu this season, with manager Carlo Ancelotti favouring the partnership of Sergio Ramos and Pepe in the heart of his side's defence.