Should Jürgen Klopp be worried? No.
Lewandowski isn't the first and won't be the last striker fortunate enough to work under Klopp.
Michael Thurk, 2001-06, 56 goals in 148 league games
He didn't click with Wolfgang Frank, Dirk Karkuth, René Vandereycken or Eckhard Krautzun.
It wasn't a mere coincidence that he started scoring, five goals in a four-game stretch, as soon as Jürgen took over.
Post-Klopp: Defected to Rhine-Main rival Eintracht Frankfurt, which didn't work out. Then went to Bundesliga hopefuls Augsburg and led them to promotion, only to be forced out of the club due to "technical reasons".
Andriy Voronin, 2002-03, 20 goals in 31 league games
He was so desperate to make it after a frustrating spell with Borussia Mönchengladbach (via Igor Linnyk at UEFA.com):
The team was falling apart, the coaches were changing very quickly, and each of them was keen to use experienced players to keep the club alive.
I was asking for a chance, but it never came.
In despair, I was ready to leave and go wherever I could, even to Mainz, who were bottom of 2. Bundesliga then.
The combination of Blaise Nkufo leaving for Hannover 96 and the appointment of Jürgen, a former Mainz stalwart, enabled Andriy to maximise his ability with a young, enthusiastic and open-minded manager.
Klopp, whose kicker player rating of 3.94 during his last season as a footballer, would've placed him at No. 195 if he had featured in enough games to get on the list.
Two seasons later, he was managing kicker's highest rated 2. Bundesliga player.
Voronin reflected on his experience with Mainz last October (via Mainz05.de):
Mainz was my spring board and I was able to jump pretty high after my contract with Mainz.
I had a lot of fun playing football, especially the last two years, when I played under Jürgen Klopp.
The 05ers have done their business really well, back then with Klopp and now with Tuchel.
Post-Klopp: Played for seven different clubs since, one of which was Liverpool, and has yet to surpass his 20-goal haul under 'Kloppo'.
During Andriy's tenure with the Reds, he constantly moaned about life in England and habitually choked in front of goal.
When he was on loan at Fortuna Düsseldorf, he told the club he was sick but went out clubbing the same night.
Mohamed Zidan, 2005-07, 35 goals in 107 league games
He had the world at his feet during the season when Stuttgart, Schalke and Werder Bremen finished 1-2-3 in the Bundesliga.
Arrogant, audacious and supremely gifted.
Jürgen managed to push Zidan to a level where you thought: "This guy could play for Barcelona," and it wasn't just a professional relationship (via Bundesliga.com):
Jürgen Klopp is like a friend.
One look is enough for me to understand what he wants from me. I can discuss all my problems with him. Even private ones.
Something like that is great for one's self-confidence.
He re-united with Klopp at Borussia Dortmund but injuries had curtailed the Egyptian's career and he was just another player, rather than being the man.
Post-Klopp: Enjoyed a fairy-tale return with Mainz (in his third stint at the club) under Thomas Tuchel and unsurprisingly, Mohamed transferred again, despite finding himself in the situation he's always preferred—being the big fish in the small pond.
Félix Borja, 2007-08, 17 goals in 32 league games
The Ecuadorian wasn't even a weekly starter for Olympiacos, so who knows what Jürgen saw in Borja, whose famous teammate at the time was former FIFA World Cup winner Rivaldo.
Post-Klopp: The season Klopp left for Dortmund was the season Félix's hot goal-scoring streak stopped. He didn't look a Bundesliga striker under Jürgen's replacement Jørn Andersen.
Lucas Barrios, 2009-12, 39 goals in 82 league games
Coca-Cola or Colo-Colo?
European scouts were descending upon this Chilean club to see if Humberto Suazo was the real deal.
After he left for Mexican team Monterrey, Barrios started scoring for fun, so scouts rushed back to Chile—it was wonderful publicity for Colo-Colo.
Klopp convinced Lucas to call BVB home and the Paraguayan international was an instant hit with 23 goals in his first season.
When Shinji Kagawa arrived from Cerezo Osaka, he took a liking to Barrios, who was willing to graft for the Japanese.
The turning point in Lucas' career at Dortmund was getting injured at the Copa América, to which Jürgen blamed the Paraguayan FA (via ESPN FC): "The injury is far worse than Paraguay's team doctor had told us. This is very annoying and casts a shadow over our relationship with the Paraguayan Football Association."
Post-Klopp: Joined Asia's answer to Manchester City, Guangzhou Evergrande (managed by World Cup winner Marcello Lippi) and has failed to meet expectations.
Barrios can't even score against Muangthong United
Evergrande should fire Lucas and give his wages as a bonus to Elkeson, who should be playing in Europe.
Robert Lewandowski, 2010-13, 53 goals in 94 league games
Jürgen has a fascination with Poles: Lewandowski, Jakub Błaszczykowski and Łukasz Piszczek.
Perhaps, Klopp grew up a fan of Kazimierz Deyna, who was a Bronze Ball recipient during the 1974 FIFA World Cup, which were hosted by West Germany.
Or, Jürgen wondered if he could find his "Artur Wichniarek", who won the 2. Bundesliga Golden Boot two seasons running for Arminia Bielefeld.
If not for Barrios' injury, Lewandowski may have looked elsewhere for regular first team football.
The Polish striker is now one of the best forwards in the world and like Kagawa, Lewandowski will regret leaving Borussia Dortmund.
- Strikers who succeed under Jürgen and then don't live up to their hype after leaving him—I call this the "Klopp affect".
- What about Lewandowski leaving? There was life before him and there will be life after him. As you read this, Jürgen is probably scouting the Polish Ekstraklasa for Lewandowski 2.0.
- RE: Lewandowski replacements? BVB can afford Edin Džeko but he doesn't have a profitable re-sell value.
- A better transfer target would be Hannover 96 forward Mame Biram Diouf, the former Manchester United player, who has freakish athleticism, can score as well as create.