In the 2007 NBA Draft Seibutis was drafted in the second round with the 50th overall pick by the Dallas Mavericks. He then played with the Mavericks' NBA Summer League team in Las Vegas, U.S., in 2007, averaging 6 points, 1 rebound, 1.6 assists and shot over 47% in 13 minutes per game over 5 games. He also played again in 2008, and averaged 2 points and 0.8 rebounds in 10.8 minutes per game over 5 games. He was ultimately dropped from the 2008 roster because of his underperforming.
This section may require cleanup to meet Wikipedia's quality standards. The specific problem is: The table is full of incorrect information (MPG, FG%); It also require "Career row" which currently doesn't exist. (November 2014)