Things looked messy for the French side after their opening Ligue 1 defeat to Rennes, when Adrien Rabiot and Jonathan Rowe clashed in the dressing room and were quickly sold.
Since then, Marseille have looked like a different team. They beat PSG in Le Classique, got an away win against Strasbourg, and then put Ajax under the pump at the Stade Velodrome. Their only setback was a stinging 2-1 defeat to Real Madrid last week.
The former Brighton manager praised the way his players are working and enjoying themselves again, aiming praise at Aubameyang for giving the captain's armband to Pierre-Emile Hojbjerg when the midfielder came on in the second half.
"I like the way my players work, the fun they have, and the relationship they create with the fans," he said after the game. "Aubameyang took off his armband when Hojbjerg came on, and he had the humility to give it to him without anyone asking him."
De Zerbi claims it was the end of the transfer window that flipped the mood, adding: "I think something changed when the transfer window ended, when [Nayef] Aguerd, [Benjamin] Pavard, [Matt] O'Riley, [Hamed] Traore, and [Arthur] Vermeeren arrived. That’s where things started. The good mood returned, and the optimism too."