Northern Ireland sprinters Jason Smyth and Amy Foster were outside the Olympic 100m qualifying standards in their latest races in the United States.
Paralympic star Smyth, 28, had times of 10.47 and 10.45 seconds in the Spring Invitational meeting at Clermont.
Smyth will need to run 10.16 to qualify for the Olympics before he defends his Paralympic 100m title in Rio a few weeks later.
Foster, 27, ran times of 11.69 and 11.54 at the same meeting.
The County Down woman will need to cut 0.08 seconds off her personal best and Northern Ireland record of 11.40 to book her Olympic spot in Brazil.
Both athletes will have more races in the US in the coming weeks.
Smyth was in action on the Florida track where he was based from 2011-13.
The County Londonderry man set his personal best of 10.22 at Clermont in 2011.
That time saw him missing out on qualification for the London Olympics 100m by 0.04 although he did successfully defend his T13 Paralympic sprint titles in 2012.
Smyth's career since then has been badly affected by a knee injury, although he has regained fitness over the last eight months after undergoing surgery.