Thomas Tuchel's view of football was changed by Ralf Rangnick and in Ralph Hasenhuttl he is looking forward to going up against another coach who worked alongside him.

Chelsea head to Southampton on Saturday and Tuchel will pit his wits against Hasenhuttl, who coached RB Leipzig during Rangnick's time as director of football at the Red Bull Arena.

Tuchel was a defender at Ulm for Rangnick between 1997 and 1998 and, following the premature end to his playing career due to a knee injury, was hired as a youth coach at Stuttgart by him two years later.

Rangnick is credited with revolutionising German football by introducing an intense high-pressing, counter-attacking style that was widely adopted.

His influence on Tuchel is clear, with Chelsea allowing the fewest opposition passes per defensive action (PPDA) in the Premier League since his first game in charge against Wolves on January 27.

Across the entire season, Southampton rank fourth in the league with a PPDA of 10.7, behind only Liverpool (10.4), Chelsea (10.3) and Leeds United (8.9).

"I was a player with Ralf Rangnick. I played in the third and second division and learned from Ralf that it's not necessary to follow the striker to the toilet," Tuchel told the media.

"He made a third-division team stronger than we actually were with brand new tactics, the back four not man marking but defending in the space in a 4-4-2 or 4-5-1.

"That was a gamechanger for me to watch football games after my experience with Ralf. It was different because I had a totally different view of what's going on.

"Ralf had his influence at Leipzig when he worked with Ralph as more or less the father of everything that happened in Leipzig.

"There are many coaches influenced by this philosophy, but I truly believe everybody has to find his own style, everybody needs to be authentic. You need to be yourself. You cannot copy anybody.

"The way from Ralph is very impressive. He had a very good season at Ingolstadt, very successful at Leipzig and now a big impact with his aggressive style of playing at Southampton.

"This is the challenge that we have to face. I cannot give you a reason why there is a trend, this is too much of a question for me right now."

Tuchel is unbeaten in six games since taking over at Chelsea, winning five straight since a 0-0 draw with Wolves in his first match.

Olivier Giroud found the back of the net in their 2-0 success over Newcastle United last Monday and Tuchel intends to give the France striker time to stake his claim for a new deal, with his contract due to expire at the end of the season.

Tuchel said: "No decision is made because it's too soon to make these decisions. [It's] too soon in the season and I haven't had enough time to make these decisions because I just started three weeks ago and we need more time to get to know the group better. Everybody deserves more time to show their value.

"What I can say is that I am super happy that he's here. He's one of the top strikers in the box, he's physically strong, he has an incredible first touch and he's strong in headers.

"He did an amazing game against Newcastle. He's very strong, very positive in training, very impressive.

"Right now, he plays a key role in the squad with a lot of young offensive players. He is a key figure, maybe not because he plays every three days 96 minutes, but because of the way he behaves and with his experience on a daily basis, he has a huge impact in the most positive way.

"This is what I can say. When the decision arrives, we will make it."