Rory McIlroy, Austin Smotherman WD from Arnold Palmer Invitational

(Photo credit: Reinhold Matay-Imagn Images)

Rory McIlroy withdrew ahead of his third round Saturday at the Arnold Palmer Invitational due to a back injury.

Austin Smotherman pulled out during his round, also with a back injury, at the Bay Hil Club & Lodge in Orlando, Fla.

World No. 2 McIlroy of Northern Ireland was 4-under through two rounds at the PGA Tour's signature event, nine shots behind 36-