Frentzen would have raced at Sauber for the remainder of this season, had it not been for the small cockpit of the Sauber C21 it now emerges. Frentzen quit Arrows earlier this season following continued financial problems.
Frentzen's comments on Sauber were made to Autosport..
"It blew me away. "Sauber is the team of the future," he added.
"If you look at teams such as Williams or McLaren, they have had their peaks. Right now they are a tad behind and struggling to get in front again. Sauber is different.
Frentzen says there is a strong chance that he may be adding to his total of three race wins.