Valentino Rossi's first grand prix since announcing he will leave Ducati and return to Yamaha at the end of this season proved to be another off-pace event.
The Italian finished the Indianapolis round in seventh place, almost a minute behind race winner Dani Pedrosa (Honda), after electing simply to get his sliding Desmosedici to the chequered flag.
The seven time MotoGP champion, who had qualified eleventh, set a best lap time 1.5s slower than Pedrosa.
“In the morning practice sessions and also in today's warm-up, I was able to ride a bit better, with a pace of around 1:40.5,”said Rossi.
“In the race though, with the higher temperatures of the afternoon, the rear tyre started to slide a lot after just a few laps. The harder I tried to push, the more it slid, so I actually went slower.
“I tried to stay with the others but I closed the front twice, and I nearly crashed. At that point, I decided to make it to the finish without making mistakes.
“I'm pleased that we go directly to Brno next week because it's a track that I like a lot and last year we had a decent race.
“Then we'll also have a test where we'll try to take a good step forward with the bike because there are only seven rounds until the end and we have to do some better races.”
Team manager Vittoriano Guareschi added: “After just a few laps today, it became very difficult for Valentino to ride. He tried to overcome the problems but couldn't manage it, and at that point he decided to take home seventh-place points. We'll try to do better at Brno.”
Team-mate Nicky Hayden was ruled out of the race after a big qualifying highside and is also in doubt for Brno.