Dortmund impressively finished top of UEFA Champions League Group D with just one defeat, scoring 14 goals, which set up a last-16 meeting with Juventus.
And yet Klopp's men went into the mid-season break in the Bundesliga's bottom two, seemingly embroiled in a relegation battle.
For a club more used to fighting it out at the summit with Bayern Munich, many anticipated a revival in 2015, but it took a couple of games to begin - a 1-0 home loss to Augsburg at the start of February apparently the nadir.
Wins over Freiburg, Mainz and Stuttgart have seen Dortmund climb to the relative comfort of mid-table, putting them in good shape ahead of Tuesday's trip to Turin.
Meetings between Dortmund and Juve have been surprisingly scarce, but the last one proved memorable for the German side.
Munich played host to the 1996-97 Champions League final, where Karl-Heinz Riedle scored twice and Lars Ricken was on target in a 3-1 triumph against Juve.
Dortmund's name has not been engraved on the trophy since then, with their Wembley defeat to Bayern two years ago the closest they have come.
Juve's wait has been longer. The Italians were the holders when Dortmund won it, having beaten Ajax the year before - another Champions League success secured by a side on home soil, as the final was played in Rome.
It makes for a positive omen as far as Dortmund are concerned, given that the showpiece is in Munich this season.
But advancing past Juve represents a sizeable challenge, with Massimiliano Allegri's charges unbeaten in normal time since October's Serie A reverse to Genoa.
Boasting a nine-point advantage at the top of the table, Juve look set for a fourth consecutive Italian title, but they have not made it past the last eight of the Champions League since the 2002-03 campaign, when they were eventually beaten by Milan in the final.
The hosts had Arturo Vidal back in full training on Sunday following a minor injury, while Klopp will hope the flu bug that has affected his team will clear up and increase the options at his disposal, with the likes of Erik Durm, Jakub Blaszczykowski, Mats Hummels and Jeremy Dudziak having been impacted.
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