 On January 28, 2020, Jeffress was signed by the Chicago Cubs for a 1 year, $850,000 major league contract, with possibility of Jeffress earning an additional $200,000 based on games pitched.On August 30, 2007, Jeffress was suspended for 50 games after testing positive for "a drug of abuse," which was reportedly marijuana.This was not his first positive test; he was given a warning for his first offense.