Signed as an undrafted free agent in 1997 out of Maine, Mike Flynn faced long odds just to make an NFL roster. Through sheer grit, intelligence, and versatility, he worked his way up from the practice squad into a central pillar of Baltimore's offensive line. Over a decade in Charm City, Flynn transformed from a roster-bubble longshot into an indispensable starter on the frontline of the most physical offense in franchise history.

Flynn contributed exceptional interior leverage, short-area power, and pre-snap intelligence to the offensive line. Whether positioned at right guard or executing line calls from the center position, he specialized in initiating movement on down blocks and maintaining blocks at the second level to facilitate power-running plays.

Flynn secured a position in the starting lineup as right guard during Baltimore's notable 2000 season. He commenced all four postseason games, facilitating running lanes for Jamal Lewis and Priest Holmes, while ensuring robust interior protection during the 34–7 triumph over the New York Giants in Super Bowl XXXV.

After his impressive championship run, Flynn showcased his flexibility by moving to center in 2002. Over the next six seasons, he became the main thinker of the offensive line, skillfully calling out blitz fronts and making important pre-snap protection adjustments. In 2003, Flynn played a key role as an interior force on an offensive line that helped Jamal Lewis achieve his famous 2,066-yard rushing season.

Flynn spent his entire 10-year NFL career exclusively in Baltimore (1998–2007). Known for his durability and steady work ethic, he played in 134 regular-season games, making 115 starts for the franchise.