Andrea Dovizioso suffered with front tyre fade as the Italian rider slipped backwards to eventually finish 11th at Aragon.
Dovizioso had been as high as fifth in the early stages on the factory Ducati GP16 but tyre issues and a vibration problem with the Desmosedici forced him to slacken his pace.
“I feel pretty bad about the result today because we worked well throughout the weekend. After a very good Saturday, in which we found a very good race pace, and qualified on the second row with the fourth quickest time, I was sure that we could have fought for the podium,” he said.
“This morning in the warm-up we confirmed that we were at the same competitive level and we were ready to score a good result in the race. Unfortunately after four laps the front tyre began to lose grip, creating a number of problems, and then I started to feel a strong vibration. Obviously I had to slow down my pace, especially because I was worried about the situation, and I lost a lot of positions in the last few laps,” added Dovizioso.
“Now we have to try and understand the reasons together with Michelin. The fact remains that we had been working well throughout the weekend and ending the race in 11th place is really disappointing.”
Compatriot Michele Pirro, who was filling in for the injured Andrea Iannone once again, finished one place behind Dovizioso in 12th.
Pirro also experienced an unusual vibration problem with his bike and was left disappointed after targeting a top ten finish at the Spanish circuit.
“The weekend was a bit complicated for me: I missed the first session on Friday and we had a few problems yesterday so I wasn't able to qualify well and had to start down the grid,” he said.
“Today's aim was to finish in the top ten but unfortunately the battle in the early stages forced me to make some mistakes in overtaking and from half-way through the race the bike began to have a big vibration, but seeing as I didn't have a chance of catching the guys ahead of me, I just tried to finish my race.
“I'm disappointed about the result because in my opinion we had the potential to finish in the top ten.”