The Cardinals used one of their two 2020 fifth-round picks to select Thompson in this year’s Supplemental Draft.
Harrison was claimed by Arizona off waivers from the Browns earlier this offseason but was recently charged with felony assault.
Thompson, 5-10 and 186 pounds, ran the 40-yard dash in 4.47 and 4.56 seconds at his Pro Day. He also hit 33.5 inches in the vertical jump, 10-feet-4-inches in the broad jump and completed 11 reps on the bench press.
Thompson played three seasons at Washington State. In total, he recorded 190 tackles, six interceptions, 17 pass defenses, two forced fumbles and five recoveries over the course of 39 games.
Harrison, 25, was signed by the Browns as an undrafted free agent out of West Georgia in 2018. The Browns elected to waive him back in June and he was later claimed by the Cardinals.
Harrison was in the second year of his three-year, $1.71 million contract and stood to make base salaries of $570,000 and $660,000 over the next two years.
During the 2018 season, Harrison started eight games for the Browns at left tackle. He was rated by Pro Football Focus as the No. 67 offensive tackle out of 80 qualifying players.