The Briton will compete in the 100m hurdles and long jump at the London Anniversary Games at the Olympic stadium on Saturday, almost a year after securing a first Games gold in the capital.
Dogged by a persistent Achilles problem that delayed her comeback this season until Tuesday, Ennis-Hill set a personal best in javelin of 48.33m at a European Athletics Permit event at Loughborough.
The 27-year-old said competing in the hurdles on Saturday would give her a better indication of whether she will head to Moscow to try to regain a heptathlon world title she relinquished to Russian Tatyana Chernova in Daegu two years ago.
"It's going to be a good test, first to do the hurdles, then go to the long jump ... obviously trying to simulate what I'm going to have to do in Moscow," Ennis-Hill said.
"I've not been able to prepare the best I could. Tuesday was the first test and I had a good response ... I didn't react too badly.
"This is the next big test. The hurdles is more explosive and coming down on my lead leg with the damaged Achilles is going to test it ... It will be good to see how it responds the day after and day after that."
The heptathlon starts on day three of the world championships on Aug. 12 and Ennis-Hill said she needed to make an early decision on her participation.
"I'm heading in the right direction but the timing is the problem. There is not a lot of time between now and Moscow and it's just making sure I handle not just the one event," she said.
"I think Monday or Tuesday (next week) I will have to make a decision - I don't want to leave it to the last minute. I want to at least get my mind in the right zone to prepare for a world championship."
Ennis-Hill ran a personal best time of 12.54 seconds in the hurdles 12 months ago as she got her Olympic gold medal campaign off to a perfect start in front of 80,000 cheering fans.
Saturday will be the first time Ennis-Hill has competed in a track event since her Olympic triumph and she admitted the circumstances of her return could not be more different.
"The last time I hurdled was in the Olympic stadium. It was an amazing race and I've got great memories from that time," she said.
"Now I'm heading back to the Olympic stadium for my first hurdle race of the season, a completely different situation. I couldn't have been more ready last year and now it feels like I'm at the opposite end of the spectrum this year."
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