Athletics Northern Ireland has been left frustrated by the omission of Ben Reynolds from Britain's team for the European U23 Championships.
Reynolds produced a 110m hurdles qualifying mark of 13.75 last week but it was two days after UK Athletics' closing date for qualification.
Athletics NI asked the UK body to reconsider but it refused to budge.
Reynolds' Northern Ireland record set recently puts him sixth in this year's European U23 rankings.
The Northern Ireland athlete is understood to have been left hugely disappointed by his omission from the Ostrava event.
Reynolds has improved his personal best of almost half a second this season and would have fancied his chances of making the final in Ostrava and slicing more off his PB.
The news comes as Athletics Ireland announced its squad for the U23 Championship.
A 20-strong squad includes Northern Ireland athletes Adam McMullan (long jump) and Claire Wilkinson (pole vault) plus Donegal man Darren McBrearty who will compete in the 800m.
McMullan has improved his personal best to 7.61m this season while Wilkinson vaulted 3.82m in Belgium last weekend - just .02m below her PB.
Those with medal ambitions will include 400m runner Brian Gregan, 200m hopeful Steven Colvert and high jumper Kourosh Foroughi.
Ireland's European U23 team
Niamh Whelan (100/200m), Steven Colvert (200m), Chris Russell (200m), Brian Gregan (400m), Darren McBrearty (800/1500m), Anthony Leghio (800m), Paul Robinson (1500m), John Travers (1500m), David Flynn (3000m s/chase), Mairead Murphy (100H), Kalyn Sheehan (400H), Jessie Barr (400H), Tim Crowe (400H), Paul Byrne (400H), Kourosh Foroughi (high jump), Claire Wilkinson (pole vault), Colin Quirke (discus), Sara Treacy (1500m), Adam McMullan (long jump), Laura Reynolds (20K walk)