Career
He was drafted in the third round, the second player drafted by the New York Giants, the 31st player taken overall in the draft. He led the Giants in rushing in his second season and after an injury was claimed on waivers and joined the Green Bay Packers midway thru the season. As a pro, Mercein is only remembered for his performance in the Packers" game-winning drive in the 1967 NFL Championship Game, known popularly as the "Ice Bowl".
One patron died, of hypothermia, that day at Lambeau Field.
The wind chill temperature was recorded at minus 48 degrees at kickoff. He played for the Packers through 1969 and then with the Jets before retiring in 1971.