​Chelsea attacker Willian has claimed that while he is sad that outcast Diego Costa is to depart the club, he believes new signing Alvaro Morata can replace him adequately.

Manager Antonio Conte has ostracized Costa from the first team but the Spain international is yet to leave the club and has opened legal proceedings against the club who are not willing to let him go on the cheap.

New signing Alvaro Morata has arrived for a club record £60m and Willian expects the Spaniard to replace Costa's goals well.

Speaking to ​Goal, Willian said, "Everyone knows about Diego Costa's quality, the striker he is, and I am sad because he is leaving,"

"He has not yet go to any club, but Morata, who has arrived, has quality and knows how to score goals too. Me and the other players are here to give all the support to our new players, for they can earn at Chelsea what they have been doing in their previous clubs."

"Matic and Diego [Costa] are two great players. I am sad to see them leave, but I expect Matic to be happy in his new club. But Chelsea have signed Bakayoko, who made a great season at Monaco, to reinforce our team," added the 29 year old.

Wilian also praised the unity and spirit among the Chelsea squad, saying that though he spends most of his time with his fellow Brazilians, he gets along well with all the players.

"My relationship with Diego is very good. He has a way on the pitch, but he is a super good guy and very humble. He is a great friend who is unfortunately no longer with us. I only wish good things for him and all the luck in the world."

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"I have great friends in Chelsea, like Diego and David Luiz. We [Willian and Luiz] are neighbours and we are always together in and out the field. Kenedy is also a great friend, and apart from the Brazilians, I have a lot of affinity with Hazard. I get along well with all the players. The atmosphere at Chelsea is very good," he said.

The Brazil international also touched upon Chelsea's challengers for the Premier League title, stating that it will be more difficult to win the title than last season in which the Blues won the league comfortably.

"I think all of them are rivals in the battle for the title. Of course, the battle for the title is always against five or six teams, but Premier League is a very difficult championship because you cannot predict any result. You know that the last placed team is as very tough opponent as the leader."

"This season is gonna be very different than the last season. The Premier League always gets better year after year. This year we have more games and the Champions League, so we need to be more attentive, because this season will be more difficult than the last," he added.

Willian joined Chelsea in the summer of 2013 and has established himself as one of the most important members of the squad, making 181 appearances and helping the side win two Premier League titles.