Bayern Munich striker Robert Lewandowski has heralded the impact Jürgen Klopp had on him when the pair worked together at Borussia Dortmund.
Lewandowski has gone on to become one of Europe's top players, but credits Klopp with helping him settle after arriving at Dortmund from Polish side Lech Poznan in 2010.
The Poland international may be the third all-time top scorer in Bundesliga history, but when he joined Dortmund as a 21-year-old, it took some time, and the influence of Klopp, for Lewandowski to adjust to his new surroundings.
Speaking to the Polish publication Prawda Futbolu, Lewandowski said: "I joined Dortmund as a young player and initially it wasn't easy. Obviously, Jürgen wasn't my dad, but in different ways he sort of adopted that role.
"He was one of the main factors behind my development and he opened the door to the big wide world of football for me."
"He’s got charisma and knows how to create the right atmosphere in a team. On top of that, he’s able to find the right balance between fun and more serious criticism. He’s a coach you’d run through fire for."
In Lewandowski's first campaign with BVB, he only scored eight Bundesliga goals - a tally he surpassed after just five matches in the 2019/20 season. Once he had spent a year under Klopp's tutelage, he netted 22 times in his second campaign in Germany.
Since 2011, Lewandowski has never scored fewer than 17 league goals for Borussia Dortmund or Bayern Munich.
Under Klopp, Lewandowski won two Bundesliga titles and lost the Champions League final in 2013 to his Bayern. Klopp left Dortmund in 2015, a year after Lewandowski joined Bayern, and even though the pair have not worked together in over five years, it's clear that the his respect for his former manager has not faded.