The Brazilian ended the day sixth on the timesheets, but was not too worried about the lap times, because most importantly Ferrari had banished the prospect of a repeat of 2012's opening test nightmare.
"I think if you compare to last year it is a completely different planet," said Massa, when asked by AUTOSPORT about how his first day's running with the new car compared to 12 months ago.
"Last year I remember we were struggling a lot to drive the car. It was tricky to keep the car on the track, so this year the base on the car is completely different to last year.
"The car is much more balanced. I felt a good direction on the rear of the car as well, with traction. This is a track that is very difficult on the rear, degradation is very high. I would say that the difference to last year is huge."
Massa said early issues with the F138 have cropped up - like the need to improve cooling in the cockpit - but there were no alarm bells ringing about significant performance problems.
"I don't think it is a difficult thing to fix," he said. "I am not disappointed definitely.
"The 1m18.8s [lap time of Jenson Button] is an incredible time definitely, but the 1m19.7s [of second fastest Mark Webber] I don't think is.
"If you look at the first day, looking at how we ran, how we drove and the direction we had for the first day, I am not really disappointed.
"There is a lot to do, a lot to work on, a lot to develop on the car for the first race. That is clear. But I am not disappointed."