Mercedes has taken a new front wing to Mexico that some speculated a week ago in Austin may be illegal.
It appears that the small winglets on the design, apparently to produce an 'outwash' effect that is against the spirit of the 2022 rules, have now been removed.
Engineering boss Andrew Shovlin denies concerns about illegality is why Mercedes did not use the wing in the US.
"The reason we didn't run it in Austin was that we only had one," he said.
"So if we had damaged it in qualifying, that would have meant that we would have had to change the wing spec before the race and put the affected driver on the back of the grid."
Shovlin says Mercedes now has spares in the luggage in Mexico "so we'll try it on Friday".
Technical director Mike Elliot, meanwhile, said the FIA green-lighted the design prior to Austin during a "CAD review process".
"Then they came back and said 'We're not so sure about this', but I think there is an argument to be made."
Meanwhile, some suspect that Mercedes is no longer motivated to try to chase Ferrari down for second in the constructors' championship, as that would only limit wind tunnel development time as per the regulations.
Shovlin insists that beating Ferrari is the target, even though achieving better conditions under the aerodynamic regulations would be a "small consolation prize" for losing that battle.
