Charles Leclerc was giving little away when asked about the difference the upgrade to the SF23 has made, insisting that it is too early to make an assessment.

Like Ferrari, a number of teams are running upgrades at this the 'traditional' proving ground for Formula One cars, the Italian team having opted not to follow Mercedes example and introduce the package in Monaco.

Of most interest is the Maranello outfit's decision to rethink its sidepod area, opting to emulate the downwash path taken by the likes of Red Bull.

In the opening session, Leclerc, running the old-spec car, was marginally quicker than his teammate who was running the upgrades, while in the second session, now with access to the full package, the Monegasque was slightly quicker, just 0.339s down on Verstappen.

"We had a few new parts on the car, I think it's a great track to test these new upgrades," said the youngster. "The feeling is quite okay, we still have a lot of work to do to optimise the new package, but it felt pretty good."

From the outset, the SF23 has proved competitive in qualifying but came race day the pace falls away, with both drivers describing the car's temperament as erratic.

"Step by step we're trying to push more and more the car and to go in places we haven't yet because we haven't had the time," said Leclerc. "It's just the normal process of having a new part and slowly going in the direction we want."

Asked if he expects to be able to battle for pole, he replied: "It's very difficult to answer that question because it's closer than ever. Apart from Red Bull that are in a league of their own with their car at the moment, especially in race pace.

"Everybody else seems to be more or less there, so I think the one that will be in front will be the one who does the perfect lap in qualifying and it's going to be very close."

"The first feeling is good," insisted team boss, Frederic Vasseur, "but it was a very intense session, I think for everybody.

"We had to test the prototype tyres and we did three or four small runs of a couple of laps. Let's have a look on everything and we'll see over the weekend what is the situation."

Asked about the new sidepods, he said: "It's a change, for sure, but it's not a new car. We are making a step forward, we are opening some doors for the development for the future, but it's not a complete change.

"It's quite promising," he added. "We committed on this way and let's see what the next weeks will bring to us. I think it was a tough decision, but it was a decision.

"From this upgrade, we are expecting a step forward, not a huge one, but a step forward," he admitted, "also to open some doors for the future in terms of development.

"We'll have other upgrades coming in the next couple of races. It's an opportunity also to take another direction, but even with this one, we're expecting to do a step forward."