Roman was a coach with the Carolina Panthers (1995–2001), Houston Texans (2002–2005), Baltimore Ravens (2006–2007) and the Holy Spirit High School Spartans (2008). Roman then worked under Jim Harbaugh at Stanford. In 2010, Roman was a finalist for the Broyles Award, given annually to the nation's top college football assistant coach.
When Harbaugh left Stanford to become head coach of the San Francisco 49ers, Roman followed and was named the offensive coordinator. He remained at the position until 2014. On January 12, 2015, Roman was hired by the Buffalo Bills to be their offensive coordinator under newly hired head coach Rex Ryan. On September 16, 2016, Roman was relieved of his duties after a 37-31 loss to the New York Jets.
