The Northern Irishman has not played since rupturing the anterior ligament in his left ankle early last month, an injury that prevented him from defending his British Open title at St. Andrews.
McIlroy's manager, Sean O'Flaherty, did not respond to an email seeking comment.
News that the four-times major champion plans to tee it up on the Wisconsin course this weekend is the first indication that he may defend his title at the PGA Championship, which starts next Thursday.
McIlroy won last year's event by one stroke at Valhalla in Kentucky, his second PGA title in three years, and he finished one shot out of a playoff the last time the PGA Championship was at Whistling Straits in 2010.
The 26-year-old has ruled himself out of this week's World Golf Championship event in Akron, Ohio.
Previously, he said that although his rehab was going well, he did not want to rush back before he was ready.
“I'm taking a long term view of this injury and, although rehab is progressing well, I want to come back to tournament play when I feel 100 percent healthy and 100 percent competitive,” he said in announcing his decision to skip the British Open.
A practice round at undulating Whistling Straits would give McIlroy a chance to walk the undulating layout and test his ankle in a way that playing elsewhere would not replicate.
Some medical experts initially said the injury suffered by McIlroy normally takes about 12 weeks to completely heal.
The first round of the PGA Championship will take place almost six weeks after he was injured playing soccer.
An employee at Whistling Straits told Reuters he was not allowed to comment on scheduled practice rounds by players ahead of the championship.
Getting an early look at the layout, meanwhile, was world number two Jordan Spieth, who played a round at Whistling Straits on Monday with fellow-Americans Gary Woodland and Justin Thomas, Reuters learned.
Spieth, who turned 22 last week, won the first two majors of the year before falling one shot short of the playoff at the British Open.
Should he win this week's Bridgestone Invitational, Spieth would displace McIlroy as world number one. – Reuters
Original source: McIlroy targets Saturday practice