Shani Davis withdrew after Race 1 of the 500 meters Monday night.
Problems with various ice-resurfacing machines caused a lengthy delay. But that's not why Davis dropped out.
Davis finished 18th in the first race with a time of 35.45 seconds, then withdrew to save his energy for the 1,000 on Wednesday night.
When the new start list came out, Davis' name was not on it, and he was seen riding an exercise bike in the warm-up room.
"He drew on his inner wisdom. He's focused on the 1,000," said Nathaniel Mills, the former U.S. Olympic speedskater who is serving as Davis' press attaché here in Vancouver. "He got the feeling he wanted and I think this was something he might do anyway. It was just preparation. The lengthy delay made that decision a lot easier. If he had been in medal contention, he would have pushed through.
"Above all, he wants to be fresh and ready for the 1,000, and we're inside 48 hours on that now. The 500 is always the race with the greatest risk of injury. Last year in the 500 at Single Distance Worlds, he tweaked his groin a little bit. All the coaches around him supported the decision, and there were some who didn't even want him to do one 500."
Mo Tae-bum of South Korea went on to win the event. He posted the second-best time of the opening race, then blazed around the track in a time of 34.90 seconds in the second heat to snatch the gold with a total time of 1 minute, 9.82 seconds.
Japan took the next two spots with Keiichiro Nagashima claiming silver and Joji Kato the bronze.
This race hardly went off as planned as the final 10 pairs of the first run were delayed for more than an hour past the usual ice resurfacing time because one Zamboni machine was broken and another was spreading water unevenly over the ice, at least in the judgment of some of the coaches and officials.
Between sessions, Davis said of the Zamboni-related delay: "It's part of the game. It happens. Bad ice is bad ice.''
Davis' best medal chances will be in the 1,000 and 1,500 meters. He's the defending champion and the world-record holder in the 1,000.
Information from ESPN.com's Bonnie Ford and The Associated Press contributed to this report.