Selected in the seventh round of the 1983 NFL draft by the Seattle Seahawks, he played college football for the University of Idaho in the Big Sky Conference.
Merriman had planned on playing at Northern Arizona in Flagstaff, also in the Big Sky, but a coaching change there altered his future further northward.
[6][7] As a rookie in 1983, the Seahawks beat Denver soundly in the wild card game and met favored Miami at the Orange Bowl in the divisional round.
On the ensuing kickoff, Merriman recovered a Dolphin fumble inside the Miami thirty that led to a Seattle field goal, the final score of the upset victory.
[8][9][10] Entering his sixth season in 1988, Merriman was a likely starter at weak inside linebacker, but suffered a career-ending knee injury in the second preseason game against Detroit at the Pontiac Silverdome; it occurred during a punt return in overtime.