Team GB sprinter Richard Kilty has decided not to defend his 60m World Indoor Championships title next month.
UK Athletics had offered the 26-year-old a place in the squad for the event in Portland along with James Dasaolu.
However, Kilty has instead opted to switch his focus to the outdoor season in preparation for the Rio Olympics.
"Whilst this has been a really tough decision, looking at the big picture it's the smart call," the Scot wrote on Twitter.
"This year is all about the Olympics, so going into Portland short of races and taking a gamble that I could run myself into form makes no sense when I could start to focus on my outdoor season early."
Kilty is yet to break the 10-second barrier over 100m, having run a personal best 10.05 seconds.
