McIlroy was responding to recent comments, including those of double US Open winner Curtis Strange, who suggested Woods ‘would be lying to himself’ if he went into next week’s championship saying he could win.
Woods has contested just one event since undergoing back surgery and that saw him miss the halfway cut in the recent Quicken Loans National at Congressional.
Woods is returning to Royal Liverpool at Hoylake for a first time since capturing an emotional third British Open Championship and just weeks after the death of his father and mentor, Earl.
But while Woods has contested only five events all season McIlroy, who is contesting this week’s Scottish Open at Royal Aberdeen, would not agree with Strange.
“We have all witnessed what Tiger has been able to do over his career, whether that's come back from injury and win, come back from any sort of off‑course stuff and win,” said McIlroy.
“I mean, he won the (2008) US Open on one leg, really on one leg.
“So it is 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.
“Also he wants to start to play, and he's missed a good chunk of the season and wants to at least get into the FedExCup Playoffs and try and push for a Ryder Cup spot maybe.
“We'll see what happens next week.
“But then I wouldn’t write him off completely. I still think he can do things that we have never seen from any other golfer. We'll see what happens.”
If McIlroy does have any doubts on Woods it was the long-time former World number one's decision in returning to contest last month’s Quicken Loans National.
“I was surprised to see he played at Congressional, but I saw stuff that he was planning to come back for The Open,” said McIlroy.
“If it was me, would I want to start back at a Major, under that amount of pressure?
“But he's done it for so many years and knows how to deal with it well. If he feels like he's 100 per cent and healthy to play and I read some of the comments from a couple weeks ago, said that he felt great and he hit some good drives.
“So if he feels healthy, his doctors give him the go ahead, then why not.”
McIlroy joins defending champion Phil Mickelson as 10 Major winners teeing up on the Aberdeen links gem.
It is the first occasion McIlroy has elected to play the Scottish Open since 2009 and citing the event’s move to the Castle Stuart course for three years from 2010-12 as a decision not to compete in the event.
“I missed out on Castle Stuart the last few years because I didn't really feel like it provided a true links test,” he said.
“I watched the tournament on TV but it was quite an American‑style golf course, big, wide fairways, big undulating greens.
"I didn't think it would prepare you as good as maybe going and playing some of the other top links courses there are in the area.
“So that's why I sort of took the week off before The Open the last few years and played links golf at home in Northern Ireland or went and prepared at whatever course the Open was at that year.
“But now that the Scottish Open is here at Royal Aberdeen and it's a true links test, I think a lot of guys have came to the realization that to play competitive golf and to play it on a course like this, could really benefit you going into next week.”