Lewis Hamilton joked that he was "snoozing" in his Mercedes car on Friday as both practice sessions were hit by delays. FP1 was mostly wiped out by rain at Monza, limiting the reigning world champion to just six completed laps.
"We woke up to torrential rain, which meant it was a less busy first session than normal," Hamilton said.
"We did a few laps but after that it was like having a day in the office when you don't have too much work to do - I was even snoozing in the car at one point!"
After being comprehensively outpaced by Vettel in the Belgian Grand Prix, Hamilton's 17-point championship lead looks likely to shrink yet again this weekend.
"We did plenty of laps in the afternoon in the dry and we could see that, like in Spa, we had a small gap to Ferrari on both the short and the long runs," he said.
"My laps felt pretty good, but Ferrari was a little bit quicker.
"It has been a big battle for a number of races now, and they have had a small advantage since the middle of the summer, but we are pushing as hard as we can to overcome that.
"Although we are on Ferrari's home turf, we have some great support out there and it's always a boost to see that in the grandstands."