Couples battled the effects of a bad back for much of his career and revealed in an interview with Golf magazine how Woods, who has had three back surgeries in his career, had once turned to him for advice.
"Tiger gave me one of the greatest compliments a couple of years ago," Couples said. "He said, 'Dude, how do you do this?'"
Woods pulled out of the Dubai Desert Classic with back spasms in February and, with only a few weeks to go before the Masters at Augusta, there is no timeline for his return.
But Couples thinks the 14-time major winner can be victorious once again.
"I love the guy," Couples said. "And I honestly believe he can, yeah. It's hard for Tiger because not only has he been the best player for 18, 20 years, but he works really hard on his game.
"So he's going to have to find his way of playing. When I'd have to withdraw, I used to tell my old caddie, Joey (LaCava), 'Joe, it is what it is.' I can't make my back feel better when I swing.
"It's impossible. And so now (Joe) caddies for Tiger and I think he's a perfect caddie because he knows. He can tell Tiger, 'Just get through this round.' But, yes, I think that if Tiger didn't think he could come back and win, there would be no reason for him to play."