The strange thing happened when no attempts were made at swimming's longest distance.
Instead, they swam with the fastest entry time in the final pass in the evening, while the others had to swim in the morning at the Duna Arena in Budapest.
Wellbrock has not focused on short track lately and his entry time was therefore not among the top eight. The German has taken World Championship gold on the distance in both short and long track.
His morning swim went quickly and he landed at 14:17.27.
Only one swimmer managed to beat that time in the evening, Tunisian Ahmed Jaouadi, who was 87 hundredths of a second faster.
Victor Johansson swam in the evening and broke the Swedish record by 19 hundredths, 14:34.27.
It was enough for tenth place.
I didn't even know it was a Swedish record, I had forgotten what my personal record is, he says to SVT.
The old record was seven years old.
Nice to be down at those times again. It feels very good ahead of the shorter distances, says Johansson, who also swims 400 and 800 meters freestyle at the World Championship.
The Swedish women finished sixth in the 4x100 meter freestyle relay. With both Sarah Sjöström and Michelle Coleman absent, a medal was a long shot.
They lacked 1.37 to bronze nation Canada.
The quartet Sara Junevik, Louise Hansson, Hanna Bergman, and Sofia Åstedt got the time 3:29.81.
The USA won with a world record time of 3:25.01 and were over three seconds ahead of Australia.
The USA men also broke the world record in the 4x100 meter freestyle, 3:01.66.
A total of seven world records were broken on the first day of the World Championship.
