On paper, MotoGP rookie Marc Marquez experienced his toughest day of 2013 pre-season testing with seventh place at Jerez on Sunday.
Arriving back in Spain having been quickest on all three days of the private Honda/Yamaha test at Austin, Marquez was then third fastest during the wet opening day.
However the Repsol Honda rider couldn't match that performance during the several hours of slick tyre time on Sunday afternoon, when he was 1.1s behind pace setter Valentino Rossi.
Marquez, who spent much of the day working on rear grip issues, finished seventh fastest with his best time on lap 21.
"At first I found myself riding the Moto2 lines but gradually I learnt and began taking different lines which suit the MotoGP machine better,” he said. “We worked on the rear grip and struggled to improve, maybe we spent too much time in this area. However, we fixed some problems and now we have some new issues to deal with that we must work on tomorrow"
The final day of pre-season testing takes place on Monday.