Tiger Woods won't tee off his 2015 Masters campaign until mid-afternoon on Thursday, but all the work necessary to get him to that point has been completed. And according to the former world No. 1, it was more than people anticipated.

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"I worked my ass off," the four-time Masters champion said (via ESPN)."People would never understand how much work I put into it to come back and do this again. It was sunup to sundown, and whenever I had free time. If the kids were asleep, I'd still be doing it, and then when they were in school, I'd still be doing it. So, it was a lot of work."

Woods required surgery on his back in 2014, strongly impacting his short game. The 39-year-old admitted the frustration got the best of him.

"It was more frustration than anything else because I knew what I could do, and just wasn't able to do it at the time," he added. "It would come in flashes. I would get in these modes where it would come for 10 minutes and I would just have it, just dialed in, and then I'd lose it for an hour; and then I'd get it back. And next thing you know, I'd flip to having it for an hour to 10 minutes of losing it and then it got to a point where it was just there."

Whether it was mental, physical or emotional, the setbacks appear to be behind Woods. And despite receiving the largest odds since 2008 (40-1), he fully expects to compete at Augusta National.

"I still feel the same way," Woods said. "I want to win. The whole idea is to prepare and do that and I feel like my game is finally ready to go and do that again."