On September 15, 2010,[4] he was named the first head coach of the expansion Pittsburgh Power of the Arena Football League. He led the Power to a 9–9 inaugural season, and after a 2–8 start in 2012 he was fired.
On June 30, 2016, Siegfried was named the first director of football operations for the new National Arena League. In October 2017, he was named the commissioner of the NAL for its second season.[3]
In 2024, Siegfried left the NAL and joined the West Texas Warbirds, who rebranded as the West Texas Desert Hawks for legal reasons, as their head coach. The Desert Hawks were among three teams who moved from the NAL to a revival of the Arena Football League for the 2024 season. Siegfried was fired from his coaching position June 9 without any public announcement, nine days before the Desert Hawks themselves quietly suspended operations.[5]