No more dreaming, now it's time for reality. Since the arrival of 45-year-old De Zerbi last summer, his motto of "straight to the goal" has been gradually reappearing in the minds of Marseille fans.
From direct style to positional play, while maintaining an attacking approach to football, the Italian is finally reaping the rewards of a long period of work that began back in July.
Second only to Paris Saint-Germain in Ligue 1, Marseille are well on the way to qualifying for next season's Champions League, with a chance of winning a title that has eluded them since the 2011/2012 season. The French Cup is also a target.
From renovation to construction, De Zerbi proves his worth
De Zerbi's first few months at the club have been complicated, so much so that the Brescia-born coach said after their 3-1 defeat to Auxerre in early November: "If I'm the problem, I'm ready to leave."
The reason for that comment was none other than a series of poor results at home, with the Italian explaining that he could not understand the change in his team's fortunes between a match away from the Velodrome and one in their own backyard.
But in reality, the defeat served to highlight a number of the team's shortcomings and ultimately proved to be a real turning point in their rollercoaster start to the season.
With the international break coming up, De Zerbi took the opportunity to fine-tune a number of details around the core of the side that had been defined at the start of the season. That of Geronimo Rulli, Leonardo Balerdi, Pierre-Emile Hojbjerg and Mason Greenwood.
Gone was the 4-2-3-1 with Lillian Brassier, Pol Lirola and Jonathan Rowe, replaced by a 4-3-3 with Geoffrey Kondogbia in defence, Valentin Rongier as the great returnee and Luis Henrique repositioned on one side. And that's when OM hit their stride, with five wins and one draw in six matches in all competitions.
De Zerbi's formula gradually clicked with the players. The team began to understand the coach's philosophy and positional play, as evidenced by their great goal against Lille.
As is often the case with De Zerbi, everything changed between the game plan on the team sheet and the reality on the pitch. His team switched from a 4-3-3 to a sort of 3-4-2-1 formation, with an omnipresent goalkeeper as the first line of defence. This allowed his side to break down the first line of pressure easily, given that Marseille had an extra player to play with.
At the back, the idea is to be as mobile as possible. The strikers absolutely have to get forward, the full-backs have to run deep, and the midfielders have to be able to project themselves forwards. All this with one player in the quarterback role: Hojbjerg.
European and cup objectives clearly identified
Fast-forward to the present. Having settled into their rhythm, the reality is that the club's short-term fixture list looks more affordable than that of their rivals. Marseille are not playing in Europe, unlike Monaco, Lille or Lyon, which is a big plus when it comes to the league.
But January promises to be a tough month all the same. Two perilous away games against Rennes (today) and Nice (26th of January) mean that they will have to be on their guard, while in the middle of the month, they welcome a Strasbourg side (on the 19th) who are on the comeback trail.
But here's an important statistic: Marseille are the best away team this season in Ligue 1 with 21 points from eight matches (seven wins, one loss), ahead of PSG with 18 points.
It's now up to them to double their efforts to get back into the Champions League, but that's not all. Another objective has been identified: The Coupe de France.
At least that's what De Zerbi said after the victory over St Etienne (4-0) in the third round: "We're playing the Cup to win it. As with the league, we play every game to be competitive."
"There is no priority, the cup is like the league. Our idea is to approach every match in the best possible way, and there are no matches that are more or less important," concluded De Zerbi.
Marseille face Lille in the next round of the cup on the 14th.
A finished project next summer?
To ensure the best possible results on the pitch, Marseille have put together a team of professionals capable of signing a French international like Adrien Rabiot or a striker of the calibre of Greenwood.
Pablo Longoria, Medhi Benatia, Giovanni Rossi and De Zerbi are the quartet who have been working tirelessly for the past six months to restore the club's reputation. The four of them began work last summer on a three-to-five-year project to turn the club back into a powerhouse in Ligue 1.
"Respect for the institution and the players already in place is all very well. But when you're on the pitch, there can't be any more respect. That's what I'm trying to make them understand. You have to have the character and desire that are typical of OM," the former Morocco international Benatia told beIN SPORTS.
It's a mindset that was applied last summer, but also since the start of the season.
While many players left between July and August, some new faces have not responded favourably to Benatia and De Zerbi's expectations. The perfect example is Brassier, recruited from Brest on loan with an option to buy, who has been one of the big sacrifices since the match against Auxerre. In the eyes of the Italian, a mistake made that evening condemned him to the sidelines for good, even though he had arrived as a promising youngster.
As proof, he is expected to pack his bags this winter. As are Abdoul Meite and Chancel Mbemba, the latter still at the club despite being deemed undesirable at the last transfer window.
Luiz Felipe, arriving as a free agent from Al Ittihad, is expected to bring his experience to Roberto De Zerbi's defence. In short, the work continues and is expected to be completed next summer.
And inevitably, Paul Pogba comes to mind, a player in whom Marseille have shown a genuine interest according to our information, but who will be considered at the end of the season. Other names have come to the fore, most recently that of Gianluca Scamacca, a striker well known to De Zerbi and Rossi, as the three men worked together at Sassuolo.
What's more, targeting a number nine is proof that Marseille are constantly on the lookout for something better to add to their squad, since, as a reminder, Elye Wahi and Neal Maupay already strengthened that position in August. But that doesn't seem to be enough.
In any case, there is no doubt that Marseille fans are once again entitled to dream of big things. And glory may come sooner than many expect.