Mällinen began his racing career in the 1990s driving Formula Ford and sports racers built by Lola cars in SCCA, Conference and endurance series.
In 2007, he finished third in Formula Atlantic and made his debut in IMSA Lites in the L2 class driving a Stohr sports prototype.
In 2012, Mällinen finished second in the SCCA National Championship Runoffs driving a Swift Engineering TRD 014.a for Swan Racing.
In 2014 at Laguna Seca, Mällinen started from pole position and retired while leading the race due to a gearbox issue.
In 2020 at Road America, Mällinen finished sixth in the SCCA National Championship Runoffs driving a Swift Engineering TRD 016.a for Swan Racing.