Prudius signed a development contract with World Wrestling Entertainment in 2006 and was assigned to Deep South Wrestling, WWE's farm territory. After that, he was reassigned to Ohio Valley Wrestling, where he won the OVW Heavyweight Championship. He made in debut on SmackDown as Vladimir Kozlov on April 4, 2008 and had a big push during his early months, including a clean victory over The Undertaker. At Survivor Series 2008, Kozlov faced Triple H and Edge for the WWE Championship, which he lost. At the end of 2008, he received the Slammy Award from WWE as the Breakout Star of the year, but Wrestling Observer Newsletter gave him the Most Overrated Wrestler award and the Survivor Series match was awarded with the Worst Match of the Year award. In 2009, Kozlov was assigned to WWE's third brand, ECW, where he teamed with Williams Regal and Ezekiel Jackson. After ECW closed down on, he was assigned to RAW and started a tag team with Santino Marella, winning the WWE Tag Team Championships. Prudius left WWE in 2011.