Pain Man

Four years ago when Jason Day collapsed to his knees on the ninth green at Chambers Bay during the U.S. Open, the narrative was different. The vertigo he suffered there made him a wounded hero when he decided to continue playing on his way to a top-10 finish.

That storyline has been replaced with something closer to pity. It’s not pity for his golf game — he is still No. 14 in the world and has five top-10s in 11 starts this seasons — it’s for the seemingly endless physical misery he has endured to compete at the highest level.

Although he has withdrawn from only six events in the past six seasons, it’s the constant battle with his back that has made Day’s career feel longer than Lord of the Rings. There are dots on the timeline: his withdrawal from the 2012 Masters due to an ankle injury; his title defense at this year’s Arnold Palmer Invitational that only lasted a few holes because of back pain. But it’s not about any specific struggle or moment — it’s the accumulation.

The fact that he is only 31 years old doesn’t seem to...