Centre-back Upson was forced to sit out Blues' game against Manchester Utd at the weekend having picked up a hamstring strain during training last week. The injury also forced Upson to withdraw from the England squad for the international friendly against Holland at Villa Park on wednesday night.
Heskey has missed Blues' last two league fixtures against United and Southampton with an Achilles injury he aggravated during the 2-0 FA cup 4th Round defeat against Chelsea at Stamford Bridge at the end of January.
The Blues hitman is however confident of making a return to the squad for the game against his former club this weekend.