LOUISVILLE, Ky. — For Tiger Woods, there was a familiar complaint.Yes, his back was hurting again. His performance at the PGA Championship is becoming more the norm, as well.Once the game’s most dominant player, Woods looked old and tired at Valhalla. He was surely overmatched Friday, shooting his second straight 3-over 74 to miss the cut at one of golf’s biggest events for only the fourth time in his professional career. Not that this was a big surprise. Woods was playing in only his fourth tournament since back surgery in late March, and he hasn’t been a factor in any of them. He failed to make the cut at the Quicken Loans National.He had his worst 72-hole showing in a major at the British Open.He had to withdraw on the final day of the World Golf Championship at Firestone after taking an awkward swing and hurting his back again.He showed up Wednesday at Valhalla, proclaimed himself fit — and flopped again.“I tried as hard as I could. That’s about all I’ve got,” Woods said. “Unfortunately, I just didn’t play well. Consequently, a pair of 74s is not very good.” With the cut at 1 over, Woods wasn’t even close to playing on the weekend.He was effectively done after shooting a 4-over 39 on the front nine, including a double bogey at No. 6 —where he three-putted from 18 feet — and a bogey at the par-5 seventh. He drove into a muddy bog far left of the fairway and had to punch out. He sailed his third shot over the green, and a sloppy chip came up short.