Thomas Tuchel comes across as a deep thinker and someone who continually strives for improvement, but he is also a manager who likes a laugh.

When you consider Chelsea's previous managers, such as Maurizio Sarri, Antonio Conte and Jose Mourinho, a lighter touch has proven a welcome addition to the training ground at Cobham where the mood has improved significantly since January.

Four months ago, with the dressing room split and former boss Frank Lampard set to be sacked, reaching the top four, an FA Cup final and a Champions League final would have seemed fanciful at best.

But in the space of 123 days, Tuchel has confirmed he is an inspired appointment, turning what looked like a disastrous season into one which may yet go down in history.

It would be a victory not only for his coaching credentials, but also his man-management, which allows him to push his players to their maximum with a smile on his face.

Bear-hugs and the simplicity of coaching

Tuchel has always demanded success from himself and his players, but also leaves a good impression.

He still exchanges messages with Arsenal striker Pierre Emerick-Aubameyang, who he coached at Borussia Dortmund, while former Blackburn and Tottenham midfielder Lewis Holtby credits the German with a huge part in his development at Mainz.

"He would batter me all week to keep me on my toes, even after I had a good game," Holtby said. "He's a very passionate guy, with a lot of fire in his belly but at 20, he introduced me to a level of football I wasn't used to and I will be forever grateful."

That passion has been evident on the touchlines this season when Chelsea have failed to take their chances, or during the goalless draw at Leeds when Tuchel got into a row with Leeds director Victor Orta, who was sitting in the stands.

Pushy might be one way of describing it, which partly led to his sacking at Paris St-Germain, where he fell out with the board over transfer targets.

But Chelsea players haven't minded him getting in their faces or giving them a bear-hug on the pitch after the final whistle, because he does that every day, which speaks of the bond he has quickly built with them.

Arriving at Chelsea halfway through the season has also allowed the 47-year-old to concentrate solely on coaching, in the process becoming the first manager to reach successive Champions League finals with two different clubs.

"Transfer periods can be mood breakers," Tuchel said earlier this month. "This made it a huge simplicity here because it has been only about coaching. I embrace the simplicity and I hope I can continue to live like this because it is pure fun."

According to sources there is a lot of laughter at the training ground from Tuchel and his assistants, Zsolt Lowe, Arno Michels and Benjamin Weber. Unlike some coaching teams, you can tell they are friends.

Tuchel is also described as one of the best communicators seen at the club in the Roman Abramovich era.

It is one of the lessons he learned from legendary German boss Ralf Rangnick, with whom he worked at Stuttgart and who once said: "Players follow you if they feel you make them better."

"The players felt a great connection with [Tuchel] from the first meeting, from the first game," Chelsea midfielder Mateo Kovacic said this week. "It was like he was here for two years already, so it came quite naturally, including his way of playing."

Tuchel's communication skills and fresh approach to training have taken Chelsea to the brink of a second Champions League title.

But having lost his last two major finals - last year's Champions League final with PSG and this year's FA Cup to Leicester - and with Chelsea hitting their worst form since he joined the club, he will know that this week is all about performance.

Defeat by Manchester City in Saturday's Champions League final, would make it the first time Chelsea have been trophy-less in successive seasons since Abramovich took over the club in 2003.

Tuchel's battle with 'logic'

Tuchel is also a very pragmatic man.

He gave players a clean slate when he came in, restored the likes of Antonio Rudiger and Marcos Alonso to the defence after being frozen out of the team by Lampard, and changed a side which had been conceding too many goals to a more robust 3-4-2-1 formation.

That has allowed them to take a safety-first approach by dominating games with possession and being less susceptible to counter-attacks.

"It was a really difficult task for Tuchel," says former Blues defender Frank Sinclair, who is now a coaching consultant. "As a coach myself I know how much time you need to work with players on the training ground to implement your playing style, especially when you are playing every three days.

"There was a massive turnaround in performance and you have to give him huge credit for what he has done in the short time he's had. You also have to remember he has done it with Frank Lampard's squad."

The biggest problem has been the Blues' inability to take chances.

In the 19 Premier League games under Tuchel compared to Lampard, Chelsea's expected goals total has increased from 29.8 to 33.1, but their actual goals total has dropped from 33 to 25.

For a manager who believes in the process as much as the result, he has resisted the chance to blame the likes of the misfiring Timo Werner or Kai Havertz.

But failing to use Tammy Abraham, who is the club's joint top scorer with Werner in all competitions with 12 goals, and Olivier Giroud, who showed signs of a renaissance earlier in the season, has caused confusion among fans.

"It's obviously down to the type of football Tuchel wants to play because he has two good target men in Abraham and Giroud," Sinclair says. "He doesn't want to play with an out-and-out traditional number nine.

"People have been pointing the finger at Werner but other players like Callum Hudson-Odoi, Mason Mount, Hakim Ziyech and Havertz have all missed chances as well, it has been an accumulation. I think a marquee striker is a priority for Chelsea this summer."

Perhaps Tuchel's loyalty to the likes of Werner and Havertz may yet prove costly on Saturday.

But he can point to taking Chelsea to their maximum potential in all three competitions he has been involved in, with a new striker perhaps adding the missing piece of the jigsaw.

While they reflect on that this summer, Chelsea's hierarchy can at least take solace in the fact that Tuchel has shown he is an almost perfect appointment.

Asked by BBC Sport how he has done it, Tuchel said: "I will not talk about me, I do what I can in the best way possible, I try to give all my knowledge and energy into this club and I really love where I am at the moment. That's all I can say."

The feeling seems to be mutual.