He began at the collegiate level, serving as Defensive Backs Coach at Mount Union from 2004 to 2005. Sirianni then moved to Indiana University of Pennsylvania, coaching wide receivers from 2006 to 2008, honing his skills in offensive player development. This foundational period prepared him for the leap to professional football, where he would carve out a path to one of the sports most coveted positions. Sirianni made his transition to the NFL in 2009, joining the Kansas City Chiefs as an Offensive Quality Control Coach through 2011.
His versatility was evident as he also served as Assistant Quarterbacks Coach in 2010 and Wide Receivers Coach in 2012. He then moved to the San Diego Chargers in 2013, initially as an Offensive Quality Control Coach. His tenure with the Chargers saw him advance to Quarterbacks Coach from 2014 to 2015, and then to Wide Receivers Coach from 2016 to 2017, demonstrating consistent upward trajectory and diverse experience across key offensive roles. In 2018, Siriannis career significantly progressed as he accepted the role of Offensive Coordinator for the Indianapolis Colts, a position he held until 2020.
He holds an impressive 48-20 record in his fifth campaign, marking the third-highest career winning percentage in the Super Bowl Era for head coaches with a minimum of 50 games.