The former Manchester United has committed to a one-year deal with Fiorentina with an option for another year.
Cauet told Radio FirenzeViola: "It makes no sense to present him as a reserve, he just needs to be physically well.
"He has international and global talent. Beyond the age is a goalkeeper of great depth and can also make a great contribution in terms of experience."
On fellow new signing Amir Richardson, the former Reims midfielder, Cauet also said: "This year he did very well in Ligue 1, before he had also done well in the lower leagues, he is a different player from Tessmann, who in my opinion is already ready.
"As far as Amir Richardson is concerned, he is a complete midfielder and has great potential both offensive and defensive situations are very good, he has excellent first control but he needs to improve on verticalisations."