"An architecture and real estate major in college, he enjoys reupholstering furniture. The Bills are using him as a centerpiece to reupholster their defense. Next to O.J., he's probably the best athlete on the Buffalo roster.
A first round draft pick last year, Clark had a good rookie year, but it could have been even better if the Bills had a pass rush. A regular at left corner, he led the Bill secondary with 18 pass knockdowns and intercepted two. Not a flashy type, but he could develop into one of the best in the league.
Born in Pasadena, Clark was an All-Pac 8 choice at Oregon and was Defensive Player of the Game in the Senior Bowl. He was burned occasionally as a rookie, but the overall indication was of a bright future."
-Rich Kucner, The Complete Handbook of Pro Football, 1977 Edition
"Mario started 14 games at left cornerback last year and became a very reliable performer, improving with every game. Named to the NFL All-Rookie team, he lived up to his billing as a No. 1 draft choice.
He had a pair of pass interceptions, recovered a fumble and was credited with defensing 18 passes. He was involved in 63 tackles, including 44 solo efforts.
Clark was an All-Pacific Eight selection of both AP and UPI, and an honorable mention AP All-America. He was a four-year letterman with 13 career interceptions, and the first freshman in Pacific Eight history to be named National Player of the Week when he was honored after making two interceptions in Oregon's 15-13 upset of Stanford in 1972. Mario appeared in the East-West Shrine Game and the Senior Bowl and was named defensive player of the game in the Senior Bowl.
Mario is an architecture and real estate major whose hobbies include music and re-upholstering furniture."
-Buffalo Bills 1977 Radio-TV-Radio Guide