In 1998, Nowak moved to the United States and joined the Chicago Fire for the team ’s inaugural MLS season. He promptly established himself as one of the best players in the League, leading the Fire to a MLS Cup (1998) and two US Open Cups (1998, 2000). He was elected 3 times to MLS All Star Team, 3 times as Chicago Fire MVP and 3 times as MLS Best XI including 1998 MLS Cup MVP. Nowak patrolled the Fire midfield for 114 league games, registering 26 goals and 48 assists. He played with Chicago for five seasons and retired in 2003. He was inducted as a first member of “Ring of Fire” Chicago Fire’s Hall of Fame in 2004. Whilst still playing for clubs in the United States, he became chairman of Górnik Konin in 1999. Manager Jerzy Kasalik was sacked for unexplained reasons by Nowak, despite their first place in the league, and he appointed little-known manager Jarosław Kotas. The team soon started to lose matches at an alarming rate and only just managed to escape relegation, only thanks to their good start. The 1999–2000 season proved to be a disaster. The owners decided to rename the senior team "KP Konin", whilst the reserve and junior teams used the old "Aluminium Konin" name. The club finished dead last. It then turned out that in the second half of the season plans to relocate the team to Bydgoszcz were put in place, and played under the name Zawisza SSA. In the end the relocation never came to fruition, but the team, which only amassed 8 points the entire season, was disbanded, with the club management and the chairman Piotr Nowak, who played professional football in the USA on a daily basis at the time, widely held responsible. The reserve team, which that same season was relegated from the Third Division, became the first team, and a season later (2000–01 season) managed to gain promotion, going straight back up. Under the lead of Jerzy Kasalik, the team achieved a back-to-back promotion to the Second Division, restoring the club's place after the first team was disbanded. The success however was short-lived, after in the 2003–04 season the club finished last once again. Following their relegation, many of the Aluminium players were involved in the large corruption scandal in Polish football which shook the country that season, which had a major impact on the club sponsors who all withdrew.