Glen Johnson singles out the one player Chelsea will regret selling this summer

Glen Johnson has insisted that Chelsea will regret selling one particular player this summer.

A number of stars have left Chelsea this summer as Todd Boehly and Mauricio Pochettino oversee a major clear-out following last season's disappointing campaign.

N'Golo Kante, Kai Havertz and Kalidou Koulibaly are among those to have departed already, while Mason Mount's move to Manchester United is expected to be confirmed imminently.

One departure, however, will be a major blow for Chelsea, according to Johnson, who told Betfred that Mateo Kovacic 'will thrive' in Pep Guardiola's side.

Kovacic made the move to the champions in June after four years at Chelsea, joining in a £25million deal as City look to boost their squad ahead of a Treble defence.

'I think he’s going to be one of the biggest losses for Chelsea this summer,’ Johnson said. ‘They’ve got decent money for him, but they’ve sold him to a better side that he’s going to improve.

‘It was obviously a tough decision for Chelsea to sell him to City, but he’s going to thrive at Manchester City as he’s going to be surrounded by world-class players and he himself is a world-class player.

‘It’s very good business from Manchester City’s side. They have top quality players in all positions, so Kovacic doesn’t even need to be an all-round midfielder, he just needs to be a rock for them in midfield and then play it to the fellow world-class player that’s next to him.'

The summer transfer window marks the second season in a row that will see Chelsea spend big, with several of the players bought in by Boehly last summer struggling for performances in the season.

The likes of Pierre-Emerick Aubameyang, Marc Cucurella and Koulibaly all arrived for big money yet didn't perform, but the chance is now there to rectify the mistakes.

Johnson, however, is wary, and admitted that it will be 'embarrassing' for Chelsea if their dealings don't pay off again.

‘It will be embarrassing for Chelsea if the players they’ve sold improve at their Premier League rivals and it would be even more embarrassing if the players they’ve signed for big money fail to work out,' he said.

‘They’re certainly allowing some of their big names to go to their rivals.

‘Let’s face it, Chelsea are behind the top four at the moment and they’re selling some of their best players to those teams above them, but they do have to recoup a lot of the money they’ve spent and time will tell if they’re doing the right thing.’