Dai Greene will miss the World Athletics Championships after failing to make the qualifying time.
Welshman Greene was world 400m hurdles champion in 2011, but has been hampered by injuries ever since.
The 29-year-old finished fifth in the Anniversary Games in London on Saturday in a time of 49.85 seconds - 0.35 outside the qualifying mark.
Saturday's race was Greene's last chance to make the grade before the championships which start on August 22.
Greene has a personal best of 47.84 sec, set in 2012.
The Llanelli product enjoyed a golden period between 2010 and 2012, winning Commonwealth Games, European championship and World Championship titles.
He was fourth in the London Olympics in 2012, however, he underwent three hernia operations in 2013 and has never been able to recapture that form.
This year Greene made his competitive start in the British Championships in Birmingham on 4 July when he was third.