The 1992 Masters champion, in Sydney for this week's Australian Open, said "when Tiger gets going again, our tour will get going at a better rate."
Couples said the PGA Tour was "blessed" by Woods' arrival 12 years ago, which boosted interest and sponsorship. He said it's only a matter of time before Woods overcomes his technical and emotional issues, and his play starts improving.
Couples said Woods is still the same golfer he used to be, he just isn't playing as well for "a lot of reasons."
"One would be his golf game but another would be a lot of emotions going on, a lot of tough times," Couples said.
Woods has gone more than a year without winning a tournament, following the November 2009 SUV crash that led to allegations of infidelity. His wife later divorced him.
Woods also sat out for nearly five months, including two months in a rehabilitation clinic, and changed swing coaches.