Maybe it's a good way to keep his tempo down and keep him from getting excited - plus, give himself less time to worry about contending at The Open?
Ben Crenshaw came up to Crystal Downs in 1986 after the first round of the Buick Open, to putt on much slower and steeper greens. And then he went back and shot 15 under the last three rounds to win the Buick!
Being mentally engaged and relaxed is pretty important to playing well.