Weeks after the Olympics, he lost to Wariner by a large margin at the Weltklasse Zürich, although Wariner's winning time of 43.82  seconds was still slower than Merritt's Olympic winning run. Merritt secured his fourth win over Wariner that season at the 2008 IAAF World Athletics Final. Although the two had both beaten each other that season, Merritt had won all the most important races, ending the season as the Olympic and American champion over 400  m as well as taking home the World Athletics Final payday. He opted to miss out on the 2009 indoor season to focus on improving his running and technique.