Marseille midfielder Mario Lemina claimed he can see the effect coach Marcelo Bielsa is having on the Ligue 1 club.
Bielsa is renowned for employing a high-energy style of football and for being obsessed with hard work at training.
The man known as 'El Loco' became Marseille's coach at the end of last season with the French club hoping Bielsa can lead them back up the Ligue 1 table in the upcoming campaign, after they finished sixth in 2013-14.
Lemina - a bit-part player under last season's coaches Elie Baup and Jose Anigo - has revelled in Bielsa's new set-up.
"The coach is a perfectionist and he likes things to be just so, and I'm one of the midfielders to whom he has been paying a lot of attention," Lemina told Ligue1.com.
"I'm kind of a key player in his formation and so when I get slack with my marking, the coach quickly pulls me up on it. I take it well, because it shows he's keeping an eye on me and it helps me to make progress.
"It's important for me to feel useful, even though we're just playing friendlies at the moment and everything can change once the season begins. I'm just trying to show my best side."
In his previous jobs at Athletic Bilbao and Chile, Bielsa often used a 3-1-3-3 formation with a focus on high-pressing, rapid movement of the ball and interchanging players.
According to Lemina, Bielsa appears to be introducing similar tactics at Marseille.
"The coach doesn't leave anything to chance. His methods use up a lot of energy, because his philosophy is based on a pressing game and winning the ball back high up the pitch," the 20-year-old said.
"We defend well and let the forwards be creative. The coach allows the midfielders and attackers to be free in their choices but we're no longer just running around.
"We know at which moment we should press, so that we're not wasting our energy. It's an intelligent strategy.
"Before, we would press the ball holder one after the other and it was really hard to win back possession. Now, we press effectively because everyone does it at the same time. We win the ball back high up the pitch and save our energy for attacking moves.
"When I return to the dressing room or go home, I feel like I've really worked, like I've learned things that will hold me in good stead for the future. Bielsa wants to put his mark on the side. It involves a lot of work but that's what it takes."