Penzo spent the next season with Napoli, where he initially played alongside Diego Maradona, although following the arrival of Bruno Giordano, he struggled both to score and break into the starting line-up, and ended his professional career at the end of the season in 1986. After being ruled out of the Napoli first team the following season, he joined Serie C1 side Trento for the 1987–88 season, and officially retired from football in 1988.