The Faenza-based outfit has said nothing about its new challenger, which emerged without fanfare on the opening day of this week's first session at the Circuit de Catalunya.

The reason for the silence has become clear, however, with the team planning a dramatic overhaul in time for the next test that starts next week.

The version of the STR11 that has appeared this week is a simple baseline solution, which has been created with the aim of ensuring that the team can verify the new packaging of the Ferrari 059/4 power unit with its chassis.

Furthermore, a new carbon fibre gearbox – which stopped Carlos Sainz on the first day – has needed to be proven, as has revised front and rear suspension.

However, sources have revealed that bold plans have been put in place for major changes to be delivered for the next test, where the STR11 will officially be launched.

As well as major aerodynamic changes, believed to involve wings, floor and sidepods, there are suggestions the team may introduce some 'interesting' mechanical solutions as well.

Max Verstappen got his first taste of the car on Tuesday but brought out a red flag earlier in the day following a suspected turbo problem.

Additional reporting by Franco Nugnes