McGowan participated in rookie minicamp for the Jaguars, as well as the Giants.
The Jaguars announced they waived DL Khairi Clark in a corresponding move.
McGowan, 6-1 and 210 pounds, signs with the Jaguars as an undrafted free agent out of UCF. Undrafted free agents are expected to sign three-year, $1.755 million contracts in 2019.
During his four-year college career, McGowan carried the ball 260 times for 1123 yards and 19 touchdowns. He also caught 16 passes for 95 yards.