Ferrari's fans are some of the most passionate in motorsport and head into 2019 hoping for their first Drivers' Championship since 2007. (2:30)

LE CASTELLET, France -- For all the emotion surrounding Ferrari's back and forth with the stewards on Friday, the Italian team's biggest concern going into this weekend's French Grand Prix lies elsewhere. On the evidence of Friday's practice, the gap to Mercedes at the front of the grid has only widened in France and the introduction of updates to the SF90 may not have had the desired effect.

Going into the weekend, Ferrari knew the Paul Ricard circuit would expose its car's weaknesses. The track layout is closest in nature to the Circuit de Catalunya -- the venue of Mercedes' biggest and most convincing victory over Ferrari to date this year. The return of a mix of slow- and medium-speed corners across the lap has seen Ferrari hemorrhage lap time to Mercedes, and any hope of a repeat of the close fight we saw in Canada is all but dead.

Over short runs on Friday afternoon, the gap between the fastest Mercedes and fastest Ferrari was 0.649s. On long runs it was closer to a second. In F1 terms, those gaps are massive and, for comparison's sake, bigger than the advantage Mercedes held over Ferrari during Friday practice in Spain.

Ferrari has introduced a new front wing concept for the French Grand Prix this weekend. Charles Coates/Getty Images

Over a single lap, the vast majority of that time is being lost in the final sector. In Sectors 1 and 2, the Ferrari makes up time on Paul Ricard's long straights, and Charles Leclerc's best sectors in both were less than a tenth of a second off pacesetter Valtteri Bottas. But in the final sector, which is absent of straights and sees the cars navigate a series of continuous medium speed corners, he lost 0.618s alone.

Vettel's time loss was split more evenly across the first and last sector, but the overall gap was even bigger at 0.728s. Combining the best of both drivers could theoretically narrow the gap to something around 0.4s, but perhaps most concerning of all, neither driver was close to being happy with the balance of the car.

"The feeling was not so good, to be honest," Vettel said. "[The updates] didn't bring what we were expecting, so we will see what we can try and find overnight to maybe be a bit better off tomorrow."

And that theoretical 0.4s gap is based on the assumption that Mercedes doesn't find even bigger gains in lap time overnight. We know for a fact that there is a lot more to come from Lewis Hamilton, who made a mistake on his soft-tyre run but was still 0.225s quicker than the two Ferraris based on his medium tyre banker lap.

Asked if the balance of his Mercedes was to his liking, Hamilton said: "No, definitely not. I struggled already in first practice, then made some changes for P2 and then still the general issue was still there, with a lot of snap oversteer, but I don't think it's anything we can't rectify."

Assuming both Mercedes drivers have more in the locker, it's going to take something monumental from Ferrari to turn things around. Ferrari, meanwhile, is facing the same problems it has had all season.

"I think again we are somehow OK in the first two sectors and we are suffering on the last one," Ferrari team boss Mattia Binotto said. "We are seeing very similar behaviour to Barcelona, I would say it is not unexpected because that is the characteristics you have and that is the car we have got at the moment."

Mercedes hopes to claim its eighth consecutive win of the 2019 season at Paul Ricard. VALDRIN XHEMAJ/EPA-EFE/Shutterstock

Perhaps the biggest disappointment was that Ferrari came to France with a raft of updates on its car. Some were purely test parts to determine the route of development at later races, but the new front wing, rear wing and brake ducts will remain on the car for the rest of the weekend.

There had been speculation on Friday morning that Ferrari had uncovered a silver bullet after supposedly uncovering a problem with its aero mapping and a lack of correlation between its CFD results and what was actually happening on the track. Sadly for Ferrari, such easy performance gains do not appear to be around the corner.

"I read that point but it is not true at all," Binotto said. "We do not have correlation issues. So I would say unfortunately [it's not true], because if that would have been the case then maybe we would have solved part of the performance. But it is not a correlation issue and what I read does not correspond to the truth."

In reality, we are looking at a straight fight between the two Mercedes drivers at Paul Ricard. Ferrari, meanwhile, may face more of a challenge from Max Verstappen, who had his hot lap ruined by Hamilton returning to the track in front of him at Turn 5, but was still only 0.384s off Vettel.

Long run pace suggested Verstappen was on average 0.7s per lap faster than Vettel on the soft tyre and 0.5s per lap faster on the medium. Even allowing for differing fuel loads and other Friday practice anomalies, those gaps should set off warning bells in the Ferrari garage.

If the Italian team thought its weekend started badly with the Canadian Grand Prix stewards' decision, it could still get a whole lot worse.