That's particularly true of McIlroy, who is still recovering from heel surgery late last year. The 32-year-old finished 11th at the World Cup race in New Plymouth a fortnight ago but, after a diet of just three weeks of running, she remains realistic about her targets today.
"The rehab since surgery has taken a long time but, in the last three weeks, I have taken my fitness up another level," she said. "I am still a wee way off where I would like to be but New Plymouth was a good indication that things are tracking really well.
"This weekend, I am looking for a solid race and not try to break any records or do anything crazy - just have a good run and get through the 10k pain free."
Samuels is better placed for a positive performance on the Queen St course, having barely missed out on attaining automatic qualification last year in London.
The 31-year-old is focused on an improvement in the run, after putting in additional work on the discipline she describes as her weakness, but she is aware the stakes of the race hardly allow room for fine-tuning.
"Every race you put different amounts of pressure on yourself," she said. "Especially for Kate just coming out of an injury, and for myself whether I'm on form. I need to be on form but she's sort of got an excuse.
"It definitely puts a bit more pressure on this race and we're all racing against each other."