Jessica Ennis-Hill is prepared to leave it as late as possible before committing herself to next month's World Championships.
Ennis-Hill made her first appearance since her recent heptathlon comeback at the British Championships in Birmingham, finishing third in her strongest 100m hurdles event.
The Olympic champion insists she came through her first heptathlon since London 2012 in Gotzis last month in good shape.
But she wants more evidence that she'll be competitive before getting on the plane to China.
Ennis-Hill clocked 13.10 seconds, in comparison to her 12.54 secs personal best, as Tiffany Porter defended her national title ahead of younger sister Cindy Ofili.
"I've still not made a decision and it will probably be quite a late call after the Anniversary Games in London," said Ennis.
"I really need to see where my hurdles are, I have to be running under 13 seconds. If I'm that kind of shape then I'll probably go.
"I felt great after Gotzis. I thought my Achilles would really flare up after two days competing but they were great and I've been doing some great training since. I feel much stronger and it's made the difference.
"My speed endurance is coming back and I feel in a better position. Half way through my hurdles in Gotzis I felt there was nothing left to give but this was much better
"I need to do two or three events in London to see if I'm really ready and then I'll be in a good position to make a decision. I'm really happy with where I am and I'm in a better place, I'm getting there."
Newly qualified British athlete Zharnel Hughes, the fastest teenager in history and a former training partner of Usain Bolt, was just outside the 200m championship record in a time of 20.44 seconds while Isobel Pooley bettered her British record to win the women's high jump with 1.97m.
"I just wanted to execute my race and run comfortable. I've been training hard and I'm just looking forward to representing Great Britain at the World Championships," said Hughes.
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