Pottios played fullback and linebacker for the Cougars, and was on the 1956 team that had a perfect regular season record and advanced to the WPIAL Class AA final.

[6] In his rookie year, he played in all 14 games, intercepting 2 passes and recovering 1 fumble for a defense that was 7th among 14 NFL teams in points allowed.

[7] He played in only 7 of 14 games, intercepting 1 pass and recovering 1 fumble[8] for a defense that finished 9th among 14 NFL teams in points allowed.

In 1967, he played 11 of 14 games, intercepting 1 pass and recovering 1 fumble[8] for the best defense in the league among 16 NFL teams in points allowed.

In 1970, his final year with the Rams, he regained his starting middle linebacker position, playing in all 14 games, with 2 interceptions and 2 fumbles recovered[8] for a defense that finished 4th among 26 NFL teams in points allowed.

Pottios, along with Jack Pardee, Maxie Baughan, Diron Talbert, John Wilbur and Jeff Jordan, followed head coach George Allen to the Redskins which also acquired a 1971 fifth-round pick (124th overall–traded to Green Bay Packers for Boyd Dowler) from the Rams for Marlin McKeever, first and third rounders in 1971 (10th and 63rd overall–Isiah Robertson and Dave Elmendorf respectively) and third, fourth, fifth, sixth and seventh rounders in 1972 (73rd, 99th, 125th, 151st and 177th overall–to New England Patriots, traded to Philadelphia Eagles for Joe Carollo, Bob Christiansen, Texas Southern defensive tackle Eddie Herbert and to New York Giants respectively) on January 28, 1971.

[11][12] Playing up to 1973, his team reached the playoffs all three years, inserted between outside linebackers Pardee (1971–72) or Dave Robinson (1973) and Chris Hanburger (1971–73).

However, Washington lost Super Bowl VII to the Miami Dolphins 14–7,[5] in which they could not handle the running attack led by Larry Csonka.