Knett joined Sepahan in September 2021 from the Greek football team Panetolikos as a replacement for Payam Niazmand but failed to meet the expectations.
The 31-year-old goalie parted ways with Sepahan on Tuesday and joined Foolad.
Foolad has qualified for the 2022 AFC Champions League Round of 16, where it is scheduled to play Saudi Arabian team Al-Faisaly in February.