According to L'Equipe, Marseille offered to sextuple Vaz's salary of €120,000 during more than two months of talks over a new contract, but ultimately decided to walk away from the negotiating table towards the end of last year because they were still some way short of meeting the player's wage demands.
Even then, OM reportedly weren't intent on selling Vaz in January, but once Roma met their €25m valuation, nobody at the club was going to stand in his way - not even De Zerbi.
"He was a player that made a real impact for us, but then he closed the shutters," De Zerbi explained in an interview with Viva El Futbol. "He started to train averagely. I would have played him anyway, had he deserved it.
"We're happy for him, we wish him well, he comes from a banlieue in Paris, he deserves to have a good career."
Unfortunately, Vaz's career in Italy hasn't got off to the best start, with him amassing just 170 minutes of action across eight substitute appearances to date. His lack of game time has surprised some pundits and supporters, given the size of the fee, but Gasperini is preaching patience.
"The club made a very important investment in him and the investment weighs on him a bit, because it inevitably changes perceptions around him, even though he's very young," the former Atalanta coach explained. "I'm trying to quickly understand how useful he can be to Roma in the immediate future, because he will certainly be in the future.
"We need to evaluate his performances carefully between snippets of matches and training sessions, taking into account that it's not easy to arrive in a difficult league like the Italian one midway through the season."