Napa, California (HawaiiNewsNow) - Oakland Raiders quarterback Colt Brennan could be on the field for Thursday's pre-season opener at Dallas. Colt took a handful of snaps with the Raiders' second-team offense Sunday, completing 4 of 6 throws. He also spent time with quarterbacks coach Paul Hackett after practice before heading to his room for a crash course in Oakland's offense. Raiders head coach Tom Cable said Brennan provided great insurance for Oakland who could be without reserve quarterbacks Bruce Gradkowski and Charlie Frye. Brennan was the Washington Redskins' sixth-round draft pick in 2008.