Former Chelsea midfielder and Nigeria international John Obi Mikel said he was quite slow to the pace expected of him by Jose Mourinho in his early days at the club.
"Got sent off on my first game. Mourinho killed me. The speed of the game took me a while to understand it," Mikel said in an interview with the BBC World Service's Sportsworld.
Mikel joined Chelsea in 2006 from Lyn Oslo as a 19 year-old off an impressive performance at the 2005 U-20 FIFA World Cup in Netherlands, where he finished the tournament as second best player, only behind Argentina's Lionel Messi, who led the Argentines to lift the trophy, defeating Mikel's Nigeria 1-0 in the final.
It was not too long after the tournament that european elite clubs showed interest in the Nigeria youngster.
With interests from Bayern Munich, Tottenham Hotspur, Manchester United and others, Mikel signed for Jose Mourinho-led Chelsea for €16 million.
Mikel, however, said the pace of the EPL was difficult for him to get into gear with the Chelsea team where he spent over a decade winning two Premier League titles, four FA cups, two League Cup, one Champions League and Europa League titles.
"I was a very naughty boy," Mikel said "I'll get up to speed but I was late to trainings many times. I was wearing the wrong dress codes."
But Mourinho-led Chelsea would have none of his naughtiness.
"Mourinho was very firm with me because he wanted me to learn and learn very fast because he brought me in."
According to him, "With Mourinho, there are no excuses. I was put in a very naughty corner a few times. It took me a while to understand where I am and I had to learn very fast."