Great Britain's Tom Fannon and Luke Greenbank have failed to qualify from the 50m butterfly heats in Baku.
Fannon finished first in the fourth heat, clocking a time of 25.12 seconds, but this was still not enough to see him through to the semi-finals.
Greenbank finished further adrift in the same heat, and his 25.20 meant that he too was eliminated.
Russian Federation swimmer Roman Shevliakov (24.10) set the fastest time this morning, closely followed by Croatia's Bruno Blaskovic (24.13).
Despite recording the fourth-fastest time, Russia's Vladislav Kozlov failed to qualify, as only two swimmers from each nation can qualify, with Daniil Pakhomov taking Russia's second spot in the semis.
Fannon will switch his attention to the 50m breaststroke and freestyle, while Greenbank is competing in the 100m and 200m backstroke, as well as the 400m individual medley.
