Amerson was eligible for the 1997 NFL Draft but went unselected. Instead, he played professionally in the CFL, initially being signed by the Hamilton Tiger-Cats. The team placed Amerson on their practice squad to start the season, but he was forced into action after Ted Long suffered a groin injury. Amerson started in his first career appearance against the Winnipeg Blue Bombers, catching his first career touchdown pass in the 18–33 loss. While the Tiger-Cats continued to struggle during the game and dropped to a 0–3 record, Amerson's performance was praised, with "The Hamilton Spectator" calling him "the quickest back ever". He followed his first game with a breakout performance against the heavily–favored Toronto Argonauts, running for 100 yards on 18 carries. By the end of August, Amerson led the Tiger-Cats' offense with 298 rushing yards, 12th most in the CFL despite not playing in the first two games. After being briefly sidelined with a foot injury, Amerson returned to a starting role and rushed for 139 yards against the Calgary Stampeders in late September. He finished the season with 1,044 combined rushing and receiving yards along with five touchdowns over 15 games. Amerson struggled with ball security throughout the season, recording six fumbles. The Tiger-Cats nominated Amerson as top rookie in the CFL.