Mercedes boss Toto Wolff believes Sebastian Vettel's dedication and hard work may have helped Ferrari's outstanding progress in 2017.
Wolff alluded to speculation that last year's close working relationship between Pirelli and Ferrari, when the Italian manufacturer undertook the development of its 2017 tyres, has led to the Scuderia better exploiting its tyres.
While Pirelli obviously denied any collusion with Ferrari, CEO Marco Tronchetti Provera did suggest that Vettel had perhaps worked harder on the issue than his Mercedes counterpart Lewis Hamilton.
Wolff conceded that the German's diligent and precise approach is paying dividends.
"Each driver has his own way to prepare," Wolff told Speed Week.
"One wants to be perfect and is a meticulous worker, while the other relies more on his instinct.
"Sebastian was always a worker, so perhaps he understood earlier on how to get the tyre in the right working window.
"We have to catch up now," he added.
Wolff denied however claims that Hamilton had lost his motivation this season.
"On the contrary," Wolff insisted.
"Lewis is not a problem but rather a positive influence, and I see him wanting it more than he did last year.
"Also for the team as a whole there will be no problem in this regard," he concluded.