Pottios became the starting middle linebacker of the Pittsburgh Steelers from his rookie year, 1961, up to 1965. 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. He did not play in 1962. In 1963, he played in all 14 games, intercepting 4 passes for a defense that finished 8th among 14 NFL teams in points allowed, playing alongside rookie outside linebackerAndy Russell. In 1964, he played in only 7 of 14 games, intercepting 1 pass and recovering 1 fumble for a defense that finished 9th among 14 NFL teams in points allowed. In 1965, he played in only 6 games, intercepting no pass and with no fumble recovery for a defense that finished 12th among 14 NFL teams in points allowed and a team that ended the season at 2-12.
In contrast, when Pottios joined the Rams from 1966 to 1970, with George Allen as head coach, they were above the.500 mark throughout the period and made the playoffs twice, in 1967 and 1969, with won-lost records of 11-1-2 and 11-3, respectively. Pottios was the starting middle linebacker from 1967 to 1970, playing between outside linebackers Jack Pardee and Maxie Baughan throughout. In 1966, Pottios played in 12 games, but was the backup middle linebacker to the 37-year-old Bill George who played in all 14 games. In 1967, he played 11 of 14 games, intercepting 1 pass and recovering 1 fumble for the best defense in the league among 16 NFL teams in points allowed. That team lost to the Green Bay Packers in the divisional round, in which Pottios started at middle linebacker. In 1968, he played all 14 games, recovering 4 fumbles for a defense that finished 3rd among 16 NFL teams in points allowed. But, in 1969, he played in only 5 of 14 games, replaced by Doug Woodlief. That team lost to the Minnesota Vikings in the divisional round with Woodlief as the starter. 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 for a defense that finished 4th among 26 NFL teams in points allowed.
Washington Redskins
Pottios followed his fired head coach, George Allen, along with Jack Pardee, to the Redskins in 1971, playing up to 1973, where his team reached the playoffs all three years, inserted between outside linebackers Pardee or Dave Robinson and Chris Hanburger. In 1971, Pottios played in all 14 games and had one interception for a defense that finished 4th of 26 teams in the NFL in points allowed. That team lost a divisional round game to the San Francisco 49ers in which Pottios started. In 1972, he played in only 7 games of 14 games, replaced by Harold McLinton, and recovered 1 fumble for a defense that finished 3rd of 26 teams in the NFL in points allowed. However, Pottios was the starting middle linebacker in all 3 playoff games the Redskins played that year, when they won a divisional round game against the Green Bay Packers and the NFC championship game against the Dallas Cowboys, in which the Roger Staubach-led Cowboys were limited to a miserable 169 yards of total offense and 3 points. However, Washington lost Super Bowl VII to the Miami Dolphins 14 to 7, din which they could not handle the running attack led by Larry Csonka. In 1973, his final year in the NFL, he played in only 6 of 14 games, but started a divisional round match against the Minnesota Vikings, losing his final game.
