Jurgen Klopp returns to Borussia Dortmund but how much has changed under Thomas Tuchel?

Thomas Tuchel doesn't have many new faces, but has changed the way Borussia Dortmund play

Thomas Tuchel is one of Europe's best young tacticians (Getty)

Liverpool manager Jurgen Klopp will travel to the place he once called home in what will be an emotionally charged return to Borussia Dortmund in the Europa League on Thursday night.

The German manager, who has a God-like standing among Dortmund fans, is sure to get a brilliant reception from the 81,000 people who pack into the Westfalenstadion to see the man who delivered successive Bundesliga titles and a Champions League final.

Liverpool are clearly an inferior team to Dortmund, but Klopp's knowledge of his former squad has been cited as an obvious advantage for the Reds, who can draw on his long tenure in the Rhine-Ruhr and an intimate knowledge of most of the squad.

New manager Thomas Tuchel, the man who had also replaced Klopp at previous club Mainz, was not given a huge amount of money to spend in the summer, with only three players becoming regular contributors in the first team.

In terms of personnel, Tuchel's Dortmund is extremely similar to Klopp's Dortmund. However, closer inspection shows that this season the tactics are vastly different from Klopp's side that last season ended up finishing seventh.

Under Tuchel, Dortmund are just five points away from Pep Guardiola's previously unbeatable Bayern Munich with six matches still to play.

Goalkeeper Roman Burki, bought from Freiburg, has been a huge upgrade over the erratic Roman Weidenfeller. The Swiss international is much less prone to mistakes and a commanding presence in an improved defence.

However, Weidenfeller will likely play on Thursday having started 14 Europa League games this season.

Two new faces have been massively impressive in midfield, none more so than Julian Weigl. The 20-year-old, bought from second division 1860 Munich, has been one of the standout players in Germany this season, and has been a mainstay in Tuchel's side. He has 46 appearances already this campaign and is in the running for the Young Player of the Year award.

Julian Weigl, 20, has been a revelation (Getty)

The studious, hard-working midfielder is an excellent passer and comfortable on the ball as well as being strong in the tackle; his biggest strength is his ability to read the game.

Gonzalo Castro was the one big summer signing, although the versatile midfielder has been overshadowed by the rise of Weigl. Capable of playing across the midfield or at full-back, Castro is another hard working presence who is extremely good on the ball.

Those three are the only new faces to have payed more than 25 matches for Dortmund this season, but the manager's changes have had a big impact on the way Dortmund are playing.

The only other breakout star this season has been Matthias Ginter - playing in midfield last season he started just 12 games but under Tuchel, he has been moved to centre-back and been excellent, starting 30 matches. Former Arsenal target Sven Bender, another box-to-box midfielder, has also been excellent playing in central defence.

No longer exponents of an all-out pressing and attacking game that often left the side vulnerable to the counter, this season Dormtund are playing a much more reserved style. They still press, speed and team-work is still emphasised, but they are much more patient, much more reserved, preferring to control the play with more possession. There is less running and more passing, with Tuchel fine-tuning the base model that Klopp established over his years.

Marco Reus, Henrikh Mkhitaryan and Pierre-Emerick Aubameyang have almost 70 goals between them (Getty)

The biggest change has been in the way Tuchel deploys his players - the 42-year-old has used a number of weird and wonderful formations that have given Dortmund a huge amount of tactical flexibility. During his time at Dortmund, Klopp almost exclusively stuck to his preferred 4-2-3-1 formation. Tuchel often uses that system as well, but in the last month alone he has also used a 3-1-4-2, 4-3-3 and 4-1-4-1.

In a more reserved, possession based system, Mats Hummels and Ilkay Gundogan have notably returned to their very best, world class form. Henrikh Mkhirtaryan, who has admitted he is playing with more freedom, has improved from just five goals and five assists last season to 16 goals and 20 assists in this campaign. He has formed a devastating forward line with Pierre-Emerick Aubameyang and Marco Reus, the trio scoring 69 goals between them this season.

Mainstays of Klopp's team have left, with former captain Sebastian Kehl retired and Ciro Immobile, Kevin Grosskreutz and Jakub Blaszczykowski all sold. Klopp's former captain Roman Wiedenfeller has started just one Bundesliga game, while one-time defensive rock Neven Subotic has played only 13 matches in all competitions after playing nearly 40 last term.

On the surface it may seem like Dortmund haven't changed that much since Klopp left nearly a year ago, but the Liverpool manager is likely to find a very different Borussia Dortmund to the one he left behind.