Chelsea are baffled by comments made by Diego Costa's lawyer in which he blamed the club and Antonio Conte for freezing the striker out from the first team, Standard Sport understands.

Costa's representative, Ricardo Cardoso, launched a scathing attack on Conte and Chelsea on Thursday, saying they had made it "impossible" for his client to remain at Stamford Bridge because of the way the Blues boss had "dismissed" the striker via text.

But Standard Sport understands that Chelsea are perplexed at Costa and Cardoso's stance, because Conte made it clear to the 28-year-old and his agent Jorge Mendes eight months ago that the forward would be allowed to leave this summer.

Costa's lawyer Cardoso had said to news agency EFE: "We are going to use all possible legal mechanisms to hold Chelsea responsible for their behaviour, making possible the departure of Diego Costa.

"He will formally request the transfer."

Costa has been told to stay away from Chelsea's training ground to give him time to sort out a move away from the champions after Conte revealed last month the decision to let the Spain international leave was made back in January.

However, Costa claimed he only found out he was no longer part of Conte's long-term plans via a text from the Italian coach in June, which Cardoso said was "inadmissible and inexcusable" from the Chelsea manager and said showed there is no way back for the 28-year-old at the club.

"When he was with the Spanish national team in June, he was dismissed from Chelsea by Antonio Conte through a text message... the way in which it was carried out and the fact that it came out in public shows unfair behaviour and a lack of respect for the player and it is inadmissible and inexcusable on Antonio Conte's part," Cardoso said.

Diego Costa's Chelsea controversies 8 show all Diego Costa's Chelsea controversies 1/8 Diego Costa has rarely been out of the limelight since joining Chelsea. Here we look at some of the occasions where he has grabbed the headlines. Getty Images 2/8 January 2015 Given a three-match ban by the FA for stamping on Emre Can during Chelsea's League Cup semi-final win over Liverpool. AFP/Getty Images 3/8 September 2015 Involved in a brawl during Chelsea's 2-0 win over Arsenal with Gunners boss Arsene Wenger describing his behaviour as "disgusting". Subsequently charged with violent conduct by the FA and given another three-match ban. 4/8 November 2015 Reacts petulantly after being named as an unused substitute against Spurs, throwing his bib to the floor, but is absolved of blame by boss Jose Mourinho who says he understands his player's frustration. (BT Sport) 5/8 March 2016 Sent off in Chelsea's FA Cup quarter-final defeat to Everton after appearing to spit in the direction of the referee then confronting Gareth Barry. Sees his initial two-match ban extended to three games and is also fined £20,000. AFP/Getty Images 6/8 August 2016 Involved in a controversial incident on the opening day of the season after a late challenge on West Ham goalkeeper Adrian. However Costa, who is already on a yellow card, is not punished further and goes on to score the winner. AFP/Getty Images 7/8 January 2017 Dropped from the squad for Chelsea's Premier League trip to Leicester following a disagreement with head coach Antonio Conte and his coaching staff, with an imminent £80million bid from Chinese club Tianjin Quanjian. Chelsea FC via Getty Images 8/8 June 2017 Costa revealed at the end of a title-winning season that Conte had texted him to say the striker was no longer part of his plans at Stamford Bridge. The Spaniard's public declaration was eventually embarrassing as Chelsea missed out on No.1 target Romelu Lukaku to Manchester United, leaving the Blues with no marquee deal and a wantaway forward in Costa. Getty Images

"Not only have Chelsea not intervened or denied it either in public or in private, but they have renewed Conte's contract, demonstrating they agree with the dismissal of Diego Costa and the way in which it was processed.

"This discriminatory behaviour makes it impossible for Diego Costa to return to Chelsea while Antonio Conte is the coach, there is no condition for him to continue playing at Chelsea, which has already been passed on to those responsible several times."

It is also understood the club are baffled by Cardoso's grievance with Conte's text to Costa becoming public, as it was the forward who revealed the message to reporters following Spain's 2-2 draw with Colombia in June. Standard Sport understands the text Conte sent to Costa simply re-confirmed the original decision taken in January to allow the player to find a new club.

Cardoso went on to confirm Costa's preferred destination remains Atletico Madrid, although it is believed the Spanish club have so far only offered Chelsea £26million for a player the Blues value at £50m.

AC Milan are also in the running to sign the Spain international on a permanent basis this summer as Atletico are unable to register new players until January due to their transfer ban imposed by Fifa.