Els played his first US Open at Baltusrol in 1993 and won the title at Oakmont in 1994.
The 49-year-old is playing this year on a special exemption from the US Golf Association -- which will allow him to keep an eye on his 21-year-old nephew.
"I would never in my wildest dreams have thought that I'd still be playing and he'd be playing with me at a US Open," Els said. "It's fantastic. I wish my sister and family could have been here to see it. But I'm glad to be keeping him company."
Els was also happy to have a chance to return to Pebble Beach, where he finished runner-up to a dominant Tiger Woods in the 2000 US Open and was third in 2010 behind winner Graeme McDowell.
"I love the place," he said. "If you're ever going to have a blueprint on a US Open, this is the one."
Els had no illusions about the likelihood that he'll contend for the title.
"My expectations are pretty low, but the hope is there," he said. "I just want to have a great week in my own way.
"And my nephew, if he can make the cut, it will be great, give him a lot of confidence.
"Eventually he wants to become a professional golfer," he added of Rebula, who is currently playing US collegiate golf at Auburn University.
"And this is a great learning ground, a great place for him to learn and see what it's all about. It's a good family bonding at a US Open."
Els, whose time is increasingly taken up by interests away from the course, including charity work and business concerns, said he is looking forward to his 50th birthday in October, when he can tee it up on the Champions Tour.
"I think I'm going to transition well onto the other side and play some golf on the Champions Tour and go see some of my old friends. And I can be competitive again," he said. "That's why I play the game. I love to compete. When your time is up, your time is up, and you can move on."