It’s understood that significant rain in Western Sydney has prompted last-minute resurfacing work through SMP’s Turn 8.

That has cast uncertainty over how the all-in pre-season test will play out with the Gardner layout, set to be used for this weekend’s season-opener, unable to be used on Wednesday as planned.

As it stands the shorter Druitt layout is set to be used for at least part of the pre-season test.

The 2.8km layout (compared to the 3.9km Gardner layout) still utilises the exit of Turn 8, however it is not a ‘drive’ corner subject to acceleration from lower speed.

Therefore the fresh bitumen will not be under the same stress as if the Gardner layout was in use.

An initial plan to use the Druitt layout for the entirety of Wednesday’s test is thought to have been met with resistance from some teams.

While commonly used for Supercars corporate ride days, there is scepticism from teams that it is a suitable venue for a sole pre-season test.

Another option on the table is that the test will be split across two days, with half a day on the Druitt layout on Wednesday and a second half-day on the Gardner layout on Thursday.

That would precede the Sydney 500 kicking off on the Gardner layout on Friday.

Confirmation of a final plan is expected to come from Supercars this morning (Tuesday).

New testing rules, introduced last year, limit teams to just two full test days per year, held on an all-in basis at SMP before Round 1 and then at Queensland Raceway following the final Sprint Cup round in August.