Lewis wants to see how he measures up on PGA Tour

"I didn't see anything in school for me," Lewis said. "If you're not good at something, and you're competitive, you don't really like doing it. School was frustrating. I couldn't read or couldn't really spell very well. And it wasn't really fun. I wanted to be the best at everything I did. And school was something I was bad at."

And if golf didn't work out? Lewis never considered an alternative.

"People talk about backups for their career, and that's probably a good way," he said. "But I gambled. I said, 'If I do a backup, then I'm not concentrating on the actual goal.' My full focus was on playing golf, and it paid off. I've got two years to learn as well as I can, and then I have no excuses. If you leave school at 16, there are no excuses not to do good at sport.

"It gives me pressure, but that pressure is a good thing."

Lewis played three times in America as an amateur — the Western Amateur outside Chicago, the U.S. Amateur at Erin Hills and the Jones Cup at Sea Island. For his pro debut, he picked a tough event.

The Copperhead Course at Innisbrook is regarded by some as the strongest course of the Florida swing, and it has attracted a deep field — Rose, coming off his big win at Doral; former world No. 1 Luke Donald; and Masters champion Charl Schwartzel, along with the likes of Nick Watney, Webb Simpson and Jason Day of Australia.

Lewis has solid credentials, yet he is always looking to measure himself against various players. As a kid, he admired the sweet swing and quiet demeanor of Retief Goosen. His standard as a young teenager was English amateur star Oliver Fisher. As a pro, he was inspired by Italian teen Matteo Manassero winning twice in Europe.

He is not eligible for the Masters — only a win at Innisbrook would get him to Augusta National — though Lewis is not sure he's ready.

"If I can get to the standard I want to," he said, "I'll be there in time."