"Obviously, as a past champion, this tournament is extra special to me. It consistently has the strongest field in golf and I'm disappointed to not be among those competing this year but I'm optimistic about a return in the near future," the 26-year-old said.
Masters champion Tiger Woods, holder Brooks Koepka and world number one Dustin Johnson are among the favourites to win the tournament, which starts on Thursday.
(Reporting by Rory Carroll; Editing by Ken Ferris)
