Speaking at the Aberdeen Asset Management Scottish Open at Royal Aberdeen yesterday, the Northern Irishman admitted Woods could still conjure an extraordinary performance over one of his happy grounds despite his lack of competitive action due to injury.
Woods returned to PGA Tour duties just more than a fortnight ago after back surgery in March. The former world No.1 missed the cut at the Quicken Loans National at Congressional and his next outing will be at Hoylake, the course where he won the last of his three Claret Jugs in 2006.
Woods famously winkled out a remarkable victory in the 2008 US Open - his last major triumph - with a shattered knee and McIlroy is in little doubt it will be a case of beware the injured golfer on the Wirral next week.
He said: "We have all witnessed what Tiger has been able to do over his career, whether that's come back from injury and win or come back from any sort of off-course stuff and win. I mean, he won the US Open on one leg, really.
"Is it foolish for people to write him off? I would say so. If he's playing and he's competing, he's got as good a chance as any. I wouldn't write him off completely. I still think he can do things that we have never seen from any other golfer.
"I read some of the comments from a couple weeks ago, he said that he felt great and he hit some good drives. So if he feels 100% healthy and his doctors give him the go ahead, then why not."
The speed of Woods' rehabilitation has surprised many. Graham DeLaet, the Canadian PGA Tour campaigner who has been held up in media circles as a comparison, underwent a similar operation and was on the sidelines for a year.