Former Manchester City and Newcastle United midfielder Joey Barton has urged Liverpool and Everton 'to do everything' they can in signing Chelsea outcast Diego Costa to bolster their strike force for the 2017/18 season.

The Brazil-born Spain international scored 20 goals and registered seven assists in the Premier League as the Blues went on to win the title last season. He last featured for the west London club in their 2-1 defeat to Arsenal in the FA Cup final.

Chelsea manager Antonio Conte has already informed the striker via text message that he is not included in his plans at Stamford Bridge for this campaign. Costa was not included in the Blues' pre-season squad as he continues to be in his family home in Brazil.

In an interview with the Daily Mail, Costa admitted that Chelsea are treating him like a "criminal" and has urged his current employers to sanction his move to his former club Atletico Madrid.

Barton is currently suspended from football and all football activity by the FA for admitting to a misconduct charge in relation to betting. The midfielder believes Jurgen Klopp or Ronald Koeman should persuade Costa to make a switch to Merseyside before the end of the transfer window.

"If I'm Liverpool or Everton I'm doing everything I can to sign Diego Costa," Barton told talkSPORT.

"I'm coming in now to Chelsea saying 'look, you're clearly prepared to do it having sold [Nemanja] Matic to a title rival in Man United'

"Liverpool are crying out for a forward of Costa's ilk and so are Everton. If they want to get into that top four consistently and do well in the Champions League – Everton in the Europa League – you could do a lot worse than Diego Costa.

"He (Costa) knows the model – he's done it consistently over the last few years. If I was Ronald Koeman or Jurgen Klopp I'd be on the phone to Chelsea trying to get that done."

According to the Independent, Chelsea value Costa around £44m ($57m) and will only look to sanction his sale if the interested clubs could meet their asking price.

Diego Costa
Diego Costa has not returned to Chelsea and is currently with his family home in Brazil Getty