The 29-year-old former world number one is aiming for victory in the Masters to complete his set of majors, although he has not won one since the PGA Championship in 2014.
After five top-six finishes in succession on the PGA Tour this year, Strange said victory at Sawgrass would send McIlroy to Augusta brimming with confidence in his ability to finish.
"I think that was huge," Strange, twice U.S. Open champion and working for broadcaster ESPN at the Masters, said.
"He didn't have to reminded that he hadn't finished off in the last year or so after playing well the first three days.
"To get over that little hurdle and win on really a kind of quirky golf course, similar to Augusta, to win on a big stage like that, you think about yourself differently."
McIlroy was in contention to win last year's Masters after a third-round 65 but blew his chances with a 74 on Sunday.
"If he's in contention come Sunday afternoon, it's a different Rory after winning The Players," American Strange said.
"It's such a mind game, so I think it was huge. Plus he's got the motivation. He knows what he's going up against, completing the Slam here.
"I think more than anything else, Rory has to calm down and just get the job done."
Several big-name European players are being tipped to win the title but Strange says Italian Francesco Molinari, the British Open champion, has the accuracy to mount a serious challenge.
"He's one-up on most of the players because he's going to play it in the middle of the fairway every time," Strange said.
(Reporting by Martyn Herman, editing by Ed Osmond)
