Cape Town - Cameron van der Burgh's FINA Short Course Swimming World Championships got off to a "slow" start when he failed to reach the final of the men's 100m breaststroke.
In Tuesday morning's heats, Van der Burgh qualified ninth-fastest for the semi-finals, finishing second in Heat 9 (of 10) in a time of 57.78.
In the evening's semi-finals, Van der Burgh was again ninth-fastest, this time touching the wall in fifth in 57.67.
Van der Burgh's time was 0.02 slower than the eighth - and final - qualifier for Wednesday's final.
Germany's Marco Koch posted the fastest semi-final time of 56.86.
Van der Burgh, who won the silver medal in the 100m breaststroke at the recent Rio Olympics, will be back in the pool for the 50m breaststroke on Saturday where he will be favoured to pick up a medal.
The men's 50m breaststroke is not an Olympic event.
This year's FINA short course championships are being held in Windsor, Canada.