Rebecca Adlington has the option to join Team GB's six-man 4x200m relay squad after winning the 200m freestyle final at the ASA National Championships.
The double Olympic champion recorded a time of 1:58.68s to overhaul Rebecca Turner, who had booked her place at the Olympics back in March.
Adlington's time sees her ranked fourth in the event for Team GB, but her commitments to the 400m and 800m events could see her turn down the opportunity to compete with the relay squad.
"I think you have to put in the four girls who are fresh," Adlington said. "I will have done the 400m, I will have the 800m the next day, whereas Jo [Jackson] will have done the 400m the first day. She will be fresh and ready, and have no more swims.
"It would be right if they put Jo in, she has got the most experience over 200m out of any of us girls, and she is the best relay girl I have known and I think it is only right that she is in it."
Great Britain must name six swimmers for the relay squad, four of which will compete in the finals.
Mark Langshaw
