Eight months later as the two sides prepare to face each other in the penultimate round of Group G matches in the competition, Gvardiol, who is now part of City's defence, knows he does not have to worry about a similar night of misery.
At least not from the boots of Haaland.
"I'm happy to be his teammate," Gvardiol said when asked about the difference between playing against or with Haaland.
"It wasn't just about Haaland, it was the first team on the pitch [last season], it was a hard game. As a centre back I was looking forward to facing Haaland but it didn't finish good.
"He scored five goals in 60 minutes. When I saw him getting subbed off I was happy."
City went on to win the Champions League for the first time and have made a good start in their bid to retain the trophy.
They have a 100% record in the group and a point on Tuesday would seal top spot ahead of Leipzig, who are also assured of their place in the knockout phase.
"At the beginning of the game he is nowhere, then he turns up and scores a hat trick. What he's done, I don't understand how but I enjoy him," the 21-year-old said.
"John Stones is getting better. Not to play, maybe a few minutes. Really close to coming back," he said.
On Tuesday's game, Guardiola added that the priority was making sure his side wrap up first place.
"We have to win or draw. The first step is done for both sides, congratulations Leipzig. Important to finish first, prestigious and it means the second leg of the last 16 at home. Not decisive, but a little advantage," he said.