Russia's sports minister on Saturday said Klokov pulled out for unspecified medical reasons. The Russian weightlifting federation said Akkaev, the 2011 world champion in the weight class, hasn't recovered from back surgery.
The Russian weightlifting team has yet to win a gold medal in London despite fielding one of the strongest lineups.
Gold medal favorite Oxana Slivenko withdrew from the women's 69-kilogram category because of an injury just before the start of the Summer Games.
On Friday, two Russian silver medalists equaled the results of the winners but missed the gold because of higher body weight.