There are several "lack of oxygen” warning signs near the field entrance at U.S. Air Force Academy’s Falcon Stadium, where the Colorado Avalanche host the Los Angeles Kings on Saturday night. Kings coach Todd McLellan said keeping his players' shifts short is crucial, as his team was feeling the elevation at Friday's skate. “It will come into play for us. We don’t train at this level. There were some red faces and some tongues hanging out at practice,” he said.