Boateng told Goal and DAZN of his professional drive: “Mentality is crucial. I started too late to really think about [my career]. Of course I regret that.
“As an 18-year-old, I would have needed an agent or a family to push me in the right direction. I would have liked that. But I had to fix everything myself.
“I know very well that I have also failed with my motivation, which has not always been 100 per cent there.
“If I would have had the absolute will, I would have been a starting XI player at Barcelona or would have played 10 years for Real Madrid or Manchester United.”
Boateng has never been short of admirers despite not always pushing himself as hard as he could.
Jurgen Klopp is among those to have cast admiring glances in his direction, with the current Liverpool boss having been keen on retaining an enigmatic talent following a short-term loan at Borussia Dortmund in 2009.
On a failed transfer, Boateng said: “BVB missed only one goal at the time for Champions League qualification. Had Dortmund qualified for Europe at the time, they would have bought me.
“Klopp called me personally and told me that it did not work out. I was very sad about that and the normally always tough Prince cried.
“At the time, I guessed that something big could happen in Dortmund, so I wanted to stay. But it wasn't meant to happen.”
Boateng added on Klopp – a manager he holds in the highest regard: “He knows exactly what he has to say to make you go on the pitch and die for him. He has this over all others.
“This has been seen in Dortmund and you can see it now in Liverpool.
“It even gives the players who do not play the feeling that they are important. With him as a coach there is a special feeling.”
Pressed further on what would have happened had the German tactician wanted to take him to Liverpool, Boateng said: “For Klopp I would even have gone to China!”
Such a switch is now unlikely, with Boateng waiting to discover whether Barcelona will be triggering the purchase option in his current loan agreement at Camp Nou.
The Catalan heavyweights have the chance to acquire him on a permanent basis from Sassuolo for €8 million (£7m/$9m).