The 1990 Toronto Argonauts finished in second place in the East Division with a 10–8–0 record. They appeared in the Eastern Final. After being the CFL's passing leader (331-for-597 for 4,509 yards) in 1989 he was in another blockbuster six for one player trade that sent him to the Toronto Argonauts. During Dunigan's first season with the Argonauts, he helped guide the second most prolific scoring offense in the history of the Canadian Football League to 689 points or 38.3 points per contest.