The world number nine currently lies three shots behind clubhouse leader Bill Haas, but he was quick to stress the difficulty of the course.
"When I saw the pin positions I thought they didn't want people to get too many under par," BBC Sport quotes him as saying. "The greens are drying out quickly, anything under par is good. By Sunday they are going to be pretty dicey."
He added: "I'm feeling good with my game and came in here relaxed to try and enjoy the week. If I can do that and not get ahead of myself then hopefully I'll give myself a great chance."
Haas currently leads the way with a score of four-under in the first round.