Defending champion Francesco Molinari withdrew from the Arnold Palmer Invitational prior to the start of the first round on Thursday because of a back injury.
A year ago, the Italian shot a final-round 64 at Bay Hill in Orlando, Fla., claiming a two-stroke win over Matthew Fitzpatrick of England.
South Korean Kyoung-Hoon Lee replaced him, teeing off with World No. 1 Rory McIlroy of Northern Ireland and No. 13 Justin Rose of England.
Molinari, 37, has not won an event since last year at Bay Hill. At the Masters Tournament last spring, he led Tiger Woods by two shots with seven holes to play but squandered the lead and has struggled to regain his form.
He has missed the cut in three of his six events on the season. Molinari was ranked as high as No. 6 last year but has fallen to No. 26.
–Field Level Media (@FieldLevelMedia)