Pierce was charged in November 2008 after he tried to drive after being kicked out of a casino. His trial was scheduled to begin Wednesday, but the judge suspected Pierce was intoxicated.
A breath test showed Pierce had a blood-alcohol level of 0.093 percent.
Negotiations for a plea agreement began. One of the conditions was that Pierce had to return to court sober the next morning to enter his plea.
Pierce has nine previous drunken driving convictions in Colorado and another one in Wyoming.