The Pata Honda rider was involved in a bad crash during pre-season testing at Phillip Island, and while he was able to turn out in the season-opening race in Australia, he was only able to register seventh and fifth-placed finishes. He followed up that performance by finishing in fifth and sixth place at the Chang International Circuit in Thailand.
Guintoli currently sits in fourth place on the standings and is 54 points behind leader Jonathan Rea, and he knows that he has to win in Aragon to start closing the gap and keep his chances of retaining his title alive.
"Aragon is about playing catch-up really, because it's clear that we haven't been fulfilling our potential in the first races of the season," Guintoli said during a press conference. "My physical condition is still improving and I'm feeling better than I was in Thailand, so that's all going in the right direction, but we need to improve our overall performance so that we can fight at the front.
"We're all working hard to realise the potential of the package, especially in the areas of engine brake and power delivery."