Cronjé improved the 27-year-old South African mark in the men's mile, previously held by Johan Fourie, on Saturday when he finished ninth at the Diamond League meeting in Eugene in 3:50.70.
"I'm starting to feel normal now again," Cronjé said late on Tuesday.
"The body and legs were very tired yesterday and today but I keep my mind busy with different things and I don't think about being tired too much."
Cronjé is the seventh fastest man this year in the field of 16 for the metric mile, having crossed the line in 3:33.31 at the Diamond League event in Doha last month.
That performance was the second fastest by a South African over the distance, slower only than his own SA record of 3:31.93 set last year, and he expected another fast race in the Italian capital.
"The goal is to stay consistent in each race," he said.
"With consistency a good time will come up along the way.
"I always hope for a tactical race because it's more my scene, but it won't be."
Meanwhile, two-lap specialist Caster Semenya will make her international season debut as she aims to gain favour from the national selectors for the Commonwealth Games in Glasgow next month.
Semenya is well outside the top-five Commonwealth ranking she needs to ensure her place in the SA team and will need a vast improvement on her best time of the year, a relatively pedestrian 2:03.05 to win the SA Senior Championships in Pretoria in April.
While the 23-year-old former world champion missed the provisional May 31 qualifying deadline, the SA Sports Confederation and Olympic Committee (SASCOC) has reportedly opened a window for possible exceptions ahead of the June 11 deadline for entries, particularly with regards to younger athletes.
Four women in the two-lap field in Rome have dipped under two minutes this year and Semenya will hope to shine by chopping a few seconds off her season's best.
Sprint star Simon Magakwe will turn out in his second major race of the season after finishing eighth in Eugene in 10.13 seconds.
Magakwe will be eager for a better start, having struggled out the blocks on Saturday, in an effort to get closer to the 9.98 SA record he set at the national championships.
American world leader Justin Gatlin, holding a season's best of 9.87, is the only other man in the line-up who has gone under 10 seconds this year.
Victor Hogan, the only other South African taking part at the meeting, will hope to draw on a world-class field in an attempt to build on his fine early season form.
Italian Hannes Kirchler is the only athlete competing in the event who has not thrown further then Hogan in his career.
Andre Olivier withdrew his name from the men's 800m start list after falling ill and javelin thrower Sunette Viljoen opted out to concentrate on her training.