It's not unusual for swimmers to not swim their best in preliminaries, saving their strength for the finals.

But, for Michael Phelps, that strategy was nearly very, very costly.

Phelps was the slowest of those who qualified for the final in the Men's 400m Individual Medley and will swim in lane 8 in the final.

Phelps was in the same heat as Hungary's Laslo Cseh, who was the silver medalist in Beijing.  Cseh led Phelps most of the way before Phelps overtook him in the final 50m.  Cseh failed to make the final.