In his initial year at Alabama, Vlachos played in one game and was subsequently redshirted.

As a redshirt sophomore in 2009 Vlachos started every game, helping pave the way for eventual Heisman Trophy winner Mark Ingram II to rush for 1658 yards and 17 touchdowns, and helped Greg McElroy throw for 2508 yard and 17 touchdowns, en route an SEC Championship and a BCS National Championship.

As a redshirt junior, Vlachos again started every game en route to a 49–7 victory over Michigan State in the 2011 Capital One Bowl.

As a redshirt senior in 2011, Vlachos again paved the way for another prolific running back, this time Trent Richardson, who rushed for 23 touchdowns and finished as a Heisman Trophy candidate.

On April 30, 2012, Vlachos was signed as an undrafted free agent by the Tennessee Titans.