They conceded a goal 16 minutes into the first half.
Then, in the second half, they conceded two more goals in the 55th and 71st minutes.
Klopp didn't bring Wang Shuo on for the entire match.
The match showed everyone that Mainz's squad was too thin; they simply didn't have the depth to compete on two fronts.
With both Hamburg and Hertha Berlin winning their matches, Mainz's league position dropped to fifth place.
After a three-game losing streak, Mainz was tied with Hertha Berlin at 52 points.
Hamburg, meanwhile, had 54 points.
Behind them was Stuttgart with 51 points.
Hoffenheim, which had earned 38 points in the first half of the season, had only managed to reach 45 points so far in the second half.
Aside from their star striker Ibisevic being sidelined for the season with a serious injury, Rangnick's team was also in terrible form. Compounded by a lack of squad depth, they simply couldn't keep up their performance in the second half of the season.
