Massa bounced back into F1 but he was arguably not the same from a competitive point of view, and for 2014 he has lost his Ferrari seat and will drive for the once-great British team Williams.
Asked if "fear" after returning to speed is something that could explain Massa's situation, Kubica told Italy's La Repubblica: "It's a complex subject.
"A driver does not simply drive. But I'm willing to bet that fear had nothing to do with Massa's problems. And I'm sure he would confirm that too.
"When you get in the car you are so concentrated that there is no room for fear. There are much bigger factors that can affect performance."
Asked what those factors might be, Kubica answered: "The bad luck to have a cannibal as a teammate."
Indeed, Kubica was particularly close to his friend Fernando Alonso, who utterly dominated at Maranello ever since he joined Massa in the garage.
And Kubica, who won the second-tier world rally championship in 2013 and is now moving into the premier category with Ford, seems to still be among those who think Alonso is better than Sebastian Vettel.
"As a driver I shouldn't answer this question," the 29-year-old responded.
"I think Vettel is in a state of grace. When you have a team and a situation that is so competitive, then it gives you an unbelievable confidence.
"Any driver in the top ten of F1, in that situation, would be invincible," added Kubica.
"In contrast, in the situation like Alonso where you are always pushing so hard to win, it's a constant struggle, and the same goes for the team, trying always extraordinary things, because the ordinary is not enough.
"Put it this way -- Vettel is in a tunnel leading straight to victory, while Alonso is in a maze where you are trying to find the way at every turn," he said.