Lewis Hamilton will avoid a German Grand Prix pitlane start if Mercedes can prove that a change of brake disc supplier does not alter the specification of the car.
Hamilton switched to Brembo brake discs ahead of qualifying at Hockenheim, where a failure during Q1 pitched him into the barriers.
Mercedes now wants to revert back to the proven Carbone Industrie version for the race, which potentially could force a pitlane start - but the FIA says there is scope for Hamilton to take up his grid spot in certain circumstances.
Although parc ferme regulations are intended to prevent teams changing parts on the car, there is some leeway for revisions to be made.
Article 34.2 of Formula 1's sporting regulations states that: "It must be clear that any replacement part a team wishes to fit is similar in mass, inertia and function to the original."
The FIA remains in discussions with Mercedes over the matter, and if the team can show that the Carbone Industrie disc is similar enough to the Brembo version then Hamilton will be able to take up his slot on the grid if he changes it.
An FIA spokesman said: "We were aware of the problem directly after qualifying and told [Mercedes executive director] Paddy Lowe that we would need to see both discs in order to establish whether or not the CI one is 'similar in mass, inertia and function' to the Brembo disc.
"Article 34.2 of the sporting regulations allows parts to be changed without penalty if they are. We will see on Sunday and [technical delegate] Jo Bauer's report will say which parts have been changed with his permission and which parts without."
The final decision from the FIA will depend on what Mercedes wishes to do, but the governing body has made it clear that there is no exemption allowed to change parts on safety grounds.
"There is no specific allowance for changes for safety reasons so we'll just have to see what Mercedes want to do once they've had the chance to deliberate," added the FIA spokesman.
"Until we know what they want to change, if anything, we won't be in a position to say what they may have to do."
If Hamilton avoids the pitlane start, he will be 20th on the grid as he has also now taken a gearbox-change penalty.