Els, a four-time Major winner, won the US Open twice in 1994 and 1997, and the British Open in 2002 and 2012.
If “The Big Easy” can pull off a surprise, as he did in the 2012 British Open at Royal Lytham and St Annes to take the Claret Jug, he would join the 25-year-old McIlroy with three different Major titles.
“Five of my last eight rounds have been in the 60s, giving me a tied-12th finish in Canada and tied-26th at last week in Bridgestone,” the 44-year-old Els said on his website.
“I want to win golf tournaments, but these results show me enough to make me feel optimistic that we can have a better final third of the season.”
Els has not won since the BMW International Open in Germany in June last year on the European Tour, but felt the time was right to notch up another victory.
“Obviously the motivation is extremely strong this week for the final major championship of the year at Valhalla.
“I played both the previous two PGA’s here tied-61st in 1996 and tied-34th in 2000. It’s good to be back. I love Nicklaus golf courses; Valhalla is always in unbelievable shape and the PGA of America sets it up very nicely.”
Keeping the ball on the short grass would be the key to scoring well, according to Els.
“You’ve got to hit it long and drive the ball well, play the game through the air and try to stay out of the juicy rough.
“It’s a tough test, but if you play well you can really score around here.”
And while American 14-time Major winner Tiger Woods would be in a race against time to see if he could get his injured back ready to tee it up, Els would in contrast need to get his mind right if he wants to contend.
“The build-up to these Major championships is all about feeling like you can get yourself ready, but at the same time not overdoing it, especially in the hot and humid weather that we’re going to experience this week in Louisville.”
Els was paired with American Rickie Fowler and Frenchman Victor Dubuisson in the first round.
Tim Clark enters perhaps the most in-form of the South Africans after his win in the Canadian Open, PGA Tour event, two weeks ago. His win was the first for a South African on the Tour in 2014, and the straight-driving Clark could well contend if he can continue his rich run of form.
Other South Africans in the field would be George Coetzee, Charl Schwartzel, Louis Oosthuizen, Rory Sabbatini, Branden Grace, Richard Sterne and Johan Kok.