Kevin-Prince Boateng's self-confidence set him apart from his team-mates at Schalke, according to Sven Hubscher, who says the player was always uninhibited against any opponent.

Boateng has played for 13 different clubs over the course of a 14-year career in European football, with Veltins-Arena being one of the few venues he stayed at for longer than just a single season.

Schalke snapped him up for €10 million from AC Milan back in August 2013, and he went on to make 58 appearances for the club across all competitions, scoring seven goals.

The mercurial playmaker impressed during his first full season in Germany, helping Schalke finish third in the Bundesliga standings.

However, Boateng was released from his contract in May 2015, after being suspended due to poor behaviour during a defeat against Cologne.

He returned to Milan briefly before making his way to Las Palmas, and has since taken in spells at Eintracht Frankfurt, Sassuolo and Barcelona.

The ex-Ghana international is now plying his trade in Turkey with Besiktas, who he joined on loan from Fiorentina in January.

Boateng has shown glimpses of his talent at a number of different clubs, but has failed to prove himself as a consistent performer or a reliable presence in the dressing room.

Hubscher, who worked with Boateng while serving as Schalke's assistant coach, recalls being impressed with the initial impact the 33-year-old had on the team.

Kevin-Prince Boateng Fiorentina 2019-20

"He was enormously confident, but also open, polite and reserved," Hubscher told Goal and SPOX. "He expresses his opinion when he thinks it is necessary, but always keeps his decency.

"Back then, we used it as the cornerstone on which our many young players could find direction in for themselves.

"We talked about him for the first time at a training camp in Doha. When it turned out that there was an opportunity to sign him, [Schalke coach] Jens Keller called him.

"Boateng just said: ‘Coach, put the No.9 shirt aside, we'll rock this thing’.

"He was exactly the experienced player we needed. I still remember his first game against Leverkusen in front of a home crowd.

"He was playing at No.6 at the time. In one situation, Max Meyer did not pass to him, but played a pass out wide.

"Since the situation was near the dugout, it was very easy to hear him (Boateng) shouting: ‘Max, play me over. Max! Max!’ Meyer just replied that Boateng had been covered.

"He replied: ‘I don't give a sh*t, play me over’. We missed having such a player like that before."

Hubscher went on to insist that Boateng's fitness issues led to his eventual departure rather than problems with his attitude, describing the midfielder as "an important personality" during his time at the club.

"It wasn’t for a personality reason, we simply could not get his susceptibility to injury under control," said the 41-year-old.

"He was no longer as efficient as we were, and he too would have wished for it to be the case, because even under Roberto Di Matteo, whom he always addressed as Mister, he was an important personality."

When asked what made Boateng stand out at Schalke, Hubscher replied: "His self-confidence. He didn't care whether we played against Leverkusen or Bayern Munich.

"He didn't give a sh*t. He simply had this self-image that everyone has to be guided by. This helped our entire team at this point. And, of course, he could also play very well."