However, chances of a giant-killing weren't being ruled out prior to the contest after Thiem beat world number three Stanislas Wawrinka in Madrid earlier this month.
"Thiem has huge potential and he could be one of the ones who's going to replace us. His tennis style is really good," he told reporters.
"What he could work on is his footwork and how he moves on the court. But apart from that, I think his speed is really good, and also the way he changes directions, he serves well. I think he has a bright future ahead of him.
"The normal thing is Dominic will be there in a short period of time, and he will have his chances to become a top star and fight for these tournaments."
Defending champion Nadal faces Leonardo Mayer in the next round.