Barcelona boss Ronald Koeman has revealed that superstar Lionel Messi was literally "a tyrant" in training during his days with the club as the Argentine maestro urged his teammates to be the best in the world.
Messi hated losing, even in practice, the Dutchman claimed.
The striker, who joined Camp Nou as a 13-year-old in 2000, went on to become one of the best players in the world, and arguably the greatest of all time. In Spain he set the pace for his teammates in both training and during matches.
"Lionel Messi has obscured everything. He was so good and he won," Koeman told Dutch outlet Voetbal International.
"Of course he had good players around him, but he made the difference. Everyone seems better than they are because of him. This is not a criticism, but an observation."
Lavishing rich praise on Messi, Koeman praised his commitment as he claimed that the former Barcelona forward would achieve a "perfect 10" in all the departments of the game.
"I knew how good he is, but it's still nice to see it up close every day. Everything you would like to teach a football player, in recognising situations, in taking the ball under pressure, in ball speed, in finishing; with Messi everything is a 10. Not normal, not normal!," Koeman added.
The former Netherlands international insisted that Messi never made light work of his training sessions – he was extremely focused on achieving his goal, which was to win everything.
"When we did a finishing practice during training, there were sometimes players who started to hit easy balls, a bit of fooling around. But with Messi everything was: boom, boom, boom, boom. Never frills, everything functional. And always wanted to win everything," Koeman explained.
"We always play a rondo before training. If the ball goes around 20 times, then the players in the middle must have an extra turn. If that happens three times in a row, the players will form two lines and the two who were in the middle then walk through and get taps on their heads and such," he stated.
"I asked Messi if it had happened to him once. 'Yes, once,' he said. In all those years. With him, the older players never lost an exercise against the young. It happened once and Messi was seriously angry about that for a week. Really, a tyrant," the Barca manager concluded.
However, with Messi now plying his trade for PSG, Barca have struggled in La Liga, where the team is "languishing" in seventh spot.
Messi, himself, is also failing to live up to expectations and is yet to score for the French club in three appearances this season.
Messi suffered another setback on Tuesday, when PSG announced that he has sustained a left knee injury and is set to miss Wednesday's game against Metz. Moreover, his participation in Saturday's match against Montpellier and the Champions League clash against Manchester City next week is also in doubt.