His final year, 1971, was easily his most productive pro season. He started in 11 of 14 Packers games, after starting only six games total in the previous two seasons. He gained playing time that had been given the previous year to Jack Clancy at wide receiver, playing split end opposite Carroll Dale. Spilis scored his only NFL touchdown in the sixth Packers season game of 1971, a road loss to the Los Angeles Rams. Spilis caught a 32-yard touchdown pass from Zeke Bratkowski in the 4th quarter, the only Packers touchdown in a 30-13 defeat. Spilis spent the entire 1972 preseason with the Packers, but in spite of his increased role in 1971, some felt he would have to fight for a job for 1972. He was released in the team's final roster cuts before the start of the regular season. The Packers replaced Spilis with rookie Leland Glass. The 1971 Packers had been one of the weakest teams in the league in the passing game. Out of 26 teams, they were last in pass attempts, 25th in completions, 25th in first downs by passing, 24th in passing yards, and 23rd in touchdown passes. After his playing days, Spilis received multiple honors from his alma mater. He was named to NIU's All-Century Team and Century's Five Best Players in 1999  and was named the #9 player in Huskie Stadium history in 2015. Spilis was also honored in 2015 as part of the 50th anniversary celebration of Huskie Stadium by being commemorated on one of 22 full-size window clings honoring NIU football greats displayed on businesses in downtown DeKalb.