Flacco is coming off of a one-year stint with the Denver Broncos, for whom he started eight games. The 35-year-old threw for 1,822 yards with six touchdowns and five interceptions before suffering a neck injury that landed him on injured reserve. The Broncos went 2-6 in his starts.
Due to a neck procedure he underwent in April, Flacco isn't expected to be cleared until some time around the start of the regular season.
Flacco spent the first 11 years of his career with the Baltimore Ravens and was the MVP of Super Bowl XLVII.