Withdrew: Jason Day, on the seventh hole of the first round of the Arnold Palmer Invitational in Orlando, Fla., citing a back injury. Day, the 2016 Bay Hill champion, walked off the Bay Hill course after dunking his second shot from 198 yards at the par-5 16th hole into water fronting the green. He stood 2 over through six holes. Day said that he has been taking anti-inflammatory medication to counter lingering soreness in his lower back. He said that he still hopes to play next week in the Players Championship at TPC Sawgrass’ Stadium Course in Ponte Vedra Beach, Fla.