Kevin de Bruyne had a bad attitude and was often sulky when playing at Chelsea under Jose Mourinho

Kevin De Bruyne’s release is regarded as one of the most egregious transfer errors in Chelsea’s history.

However, two former regulars assert that nobody could have predicted the Manchester City superstar’s future prowess.

De Bruyne is one of English football's greats

De Bruyne is a legend in English football.

The Belgian made his Blues debut for the club in 2012 for a meager £7 million, but appeared in just nine more matches for the first team before being loaned to Werder Bremen and subsequently sold to Wolfsburg.

In 2015, City paid the latter club £55 million for his services after he annihilated the Bundesliga. The rest is history.

Two former Chelsea colleagues have recounted the story of how he slipped through their fingertips to become one of the greatest creators in Premier League history and a five-time champion.

John Terry was asked on The Obi One Podcast, alongside former teammate John Obi Mikel, whether he could have witnessed De Bruyne and fellow Chelsea failure-turned-English football hero Mohamed Salah develop into great players.

Transfer news: Wolfsburg hopeful transfer of Kevin de Bruyne from Chelsea  is nearing completion | The Independent | The Independent

“Undoubtedly not,” he responded. “This is the only disappointment I have had in my time as captain; I believe I have matured over the years.”

“During those early years, when those men were there, I was likely the most disciplined and dominant member of the group in terms of our procedures.

“In fact, that was likely the first time they required an arm around the shoulder, a seat, and a conversation; I may have assisted them in settling in.”

“Therefore, considering the skill level of those players, I am disheartened with my performance as captain, and it will be a day of regret for me.” “While I am pleased with their current development, I would not have predicted they would have reached the level they have.”

Terry admitted he could have handled things better

Terry acknowledged that he initially mishandled the situation.

Mikel agreed with his former teammate completely and did not perceive ex-midfield companion De Bruyne to be doing nearly enough.

Mikel concurred, “Absolutely not,” with regard to De Bruyne and Salah.

“However, it wasn’t just you, JT; based on their skill levels at the time, Kevin De Bruyne wasn’t the most effective trainer at that time.”

“He was a member of the training staff who, presumably due to his limited playing time, was perpetually dejected, irate, and sulking.” Similar to an offspring who arrived at the playground to find no one interested in playing with him.

“I recall a time when Samuel Eto’o confronted De Bruyne on the training field; the reason he [De Bruyne] failed to put forth the effort that Eto’o desired resulted in a heated dispute between the two players.”

Samuel Eto'o 'had a huge fight with "bad trainer" Kevin De Bruyne' and Jose  Mourinho 'made Mohamed Salah cry': Chelsea old guard John Terry and John  Obi Mikel reveal how they lost

“However, we did not anticipate them to be where they are now at the time; they’ve accomplished what was necessary to become the superstars that they are today. “They deserve credit for that they have since departed.

“Today, whenever I watch Kevin De Bruyne, I wonder, ‘Is this the same guy?'”