Valentino Rossi admitted that his ninth place on the Portuguese Grand Prix grid was significantly below his and Ducati's expectations, as he blamed a front-end handling issue for the poor result.
The former champion had been fourth quickest in Friday practice, but could not match that pace today and will start on row three.
"We are very upset about the performance this afternoon and especially about the position, because our target was to fight for the second row, around fifth or sixth place, and we had that potential yesterday," said Rossi. "But today I was not able to ride in a better way. I had a problem with the front, and when I tried to push more I was too much at the limit with the front part of the bike, so more or less the problem remains the same and I cannot make it better, unfortunately. So tomorrow will be another difficult race, starting from the third row."
He said he had managed to make some progress towards the end of the session, but that another breakthrough was required if Ducati was to have any chance of a competitive race.
"At the end we made a modification to the setting and I improved the feeling and also the lap time, but still not enough," Rossi said. "We need to make another step like this to try to do a good result."
His teammate Nicky Hayden was only 13th fastest on the second Ducati, and suggested that the bike had proved too sensitive to today's cooler weather conditions after struggling with tire performance.
"Yesterday I felt pretty confident that we'd found a direction and were going in a good way," said Hayden. "I think maybe on the cooler track today the front tyre wasn't working good enough. I was going to try to use the soft front but it never came in so I had to go for the hard. I had no more softs. I saved one for the race, but [otherwise] I was out of softs."