Jordan Spieth and Rory McIlroy will try to join exclusive clubs when the 2021 PGA Championship tees off Thursday, May 20 on the Ocean Course at Kiawah Island Golf Resort in South Carolina. Spieth can become just the sixth golfer to win the career grand slam with a victory, while McIlroy could become the sixth player to win the PGA Championship more than twice. Spieth last won a major at the 2017 British Open at Royal Birkdale, while McIlroy's last major title was the 2014 PGA at Valhalla, but both seem to be peaking at the right time entering the PGA Championship 2021.

McIlroy's victory at the Wells Fargo Championship last week moved him up to the favorite at 10-1, according to the latest 2021 PGA Championship odds from William Hill Sportsbook. World No. 1 Dustin Johnson and third-ranked Jon Rahm are both 12-1, with No. 2 Justin Thomas and Bryson DeChambeau at 14-1. Before you lock in any 2021 PGA Championship picks or PGA Tour predictions, you need to see who golf insider Sal Johnson is backing.

A media legend and consummate golf insider, Johnson has a strong feel for which players have the momentum and how their games fit the courses.

Before Hideki Matsuyama won the Masters three weeks ago, Johnson made special mention of Spieth, Schauffele and Will Zalatoris as golfers to watch. He listed Spieth and Schauffele in his top three contenders and had Zalatoris as his top rookie. Zalatoris nearly caught Matsuyama and finished as runner-up, while Spieth and Schauffele tied for third.

He also knows when surging players are poised for a breakthrough. He tabbed Sungjae Im as a top contender before his first Tour win at the Honda Classic last season, then touted Tyrrell Hatton before he got his first tour victory the following week. Anyone who has followed Johnson's advice has cashed in huge.

Now Johnson, the first producer of "Inside the PGA Tour," a longtime ABC Sports golf producer who worked with Jack Nicklaus, Arnold Palmer and Greg Norman, and the founder of the world's top golf stats database, has released his highly confident 2021 PGA Championship picks, and they will surprise you.

Shockingly, the golf expert is fading Jon Rahm, who is near the top of the PGA Championship odds 2021 and is playing arguably the best golf on tour. The problem is, he hasn't been able to turn that strong play into victories. He has finished in the top 10 in nine of his past 12 events, but the 27-year-old hasn't won on tour this season and has three wins in his career. Johnson isn't sure if it is a lack of killer instinct or experience, but he isn't listing him among his favorites to win.

On the other hand, Johnson expects DeChambeau to try to overpower the Ocean Course. He is the longest driver at more than 321 yards but is 166th in accuracy and 205th in distance from the edge of the fairway. Still, DeChambeau leads the tour in scoring average (69.668), total strokes gained, and strokes gained off the tee. He also performs well on the greens, ranking 15th in strokes gained putting. He has two recent victories, including the U.S. Open.

The golf expert also is eager to see what Koepka can do after rehabbing for a month after he missed the cut at the Masters. The four-time major champion tried to grind it out at Augusta less than a month after major knee surgery. He had two top-10s in his three starts before what he called a "freak accident," including a win at Phoenix. The 31-year-old is third on tour in total strokes gained and has been excellent on the greens. He is sixth in strokes gained putting and is off in one putt more than 33 percent of the time (13th).

This week, Johnson is touting a monumental long shot. This player has been playing consistently well and quietly was near the top of the leaderboard the last time the major was played at Kiawah Island. He could pull off a stunning victory in the PGA Championship 2021, and anyone who backs this underdog could cash in huge. You can only see who it is here.

Who wins the 2021 PGA Championship? Where do Bryson DeChambeau and Brooks Koepka finish? And which huge long-shot is a must-back? Check out the odds below, then visit SportsLine to see Sal Johnson's full leaderboard, picks and analysis for the 2021 PGA Championship, all from the insider who has a strong feel for when these players are in line for a big weekend.

Rory McIlroy 10-1 Dustin Johnson 12-1 Jon Rahm 12-1 Justin Thomas 14-1 Bryson DeChambeau 14-1 Jordan Spieth 16-1 Xander Schaufele 16-1 Brooks Koepka 20-1 Collin Morikawa 22-1 Viktor Hovland 25-1 Hideki Matsuyama 25-1 Patrick Cantlay 28-1 Daniel Berger 33-1 Tyrrell Hatton 33-1 Webb Simpson 33-1 Patrick Reed 33-1 Tony Finau 33-1 Will Zalatoris 40-1 Justin Rose 40-1 Tommy Fleetwood 40-1 Cameron Smith 40-1 Scottie Scheffler 45-1 Louis Oosthuizen 50-1 Matthew Fitzpatrick 50-1 Jason Day 50-1 Paul Casey 50-1 Abraham Ancer 50-1 Sung-Jae Im 60-1 Joaquin Niemann 60-1 Adam Scott 60-1 Gary Woodland 66-1 Shane Lowry 66-1 Sergio Garcia 66-1 Marc Leishman 66-1 Harris English 66-1 Corey Conners 66-1 Sam Burns 66-1 Brian Harman 80-1 Max Homa 80-1 Garrick Higgo 80-1 Lee Westwood 80-1 Bubba Watson 80-1 Si-Woo Kim 80-1 Francesco Molinari 90-1 Billy Horschel 100-1 Matt Wallace 100-1 Rickie Fowler 100-1 Matt Kuchar 100-1 Keegan Bradley 100-1 Cameron Champ 100-1 Robert Macintyre 125-1 Kevin Kisner 125-1 Branden Grace 125-1 Jason Kokrak 125-1 Martin Kaymer 125-1 Christiaan Bezuidenhout 125-1 Kevin Na 125-1 Matt Jones 125-1 Henrik Stenson 125-1 Ian Poulter 125-1 Brendon Todd 125-1 Phil Mickelson 125-1 Sebastian Munoz 150-1 Brandt Snedeker 150-1 Alex Noren 150-1 Bernd Wiesberger 150-1 Thomas Pieters 150-1 Stewart Cink 150-1 Victor Perez 150-1 Zach Johnson 150-1 John Catlin 150-1 Mackenzie Hughes 150-1 Danny Willett 150-1 Byeong Hun An 150-1 Rasmus Hojgaard 150-1 Dylan Frittelii 175-1 Rafa Cabrera Bello 175-1 Matthias Schwab 200-1 Thomas Detry 200-1 Ryan Palmer 200-1 Joel Dahmen 200-1 Hudson Swafford 200-1 Thorbjorn Olesen 200-1 Kevin Streelman 200-1 Padraig Harrington 200-1 Tom Lewis 200-1 Adam Hadwin 200-1 Erik van Rooyen 200-1 Chez Reavie 200-1 Carlos Ortiz 200-1 Lanto Griffin 200-1 Charles Howell 250-1 Jimmy Walker 250-1 Martin Laird 250-1 Andy Sullivan 250-1 Sam Horsfield 250-1 Jason Dufner 250-1 Graeme McDowell 250-1 Omar Uresti 300-1 Jim Herman 400-1 Brian Gay 400-1 Vijay Singh 500-1 Davis Love 500-1 Y.E. Yang 500-1 Rich Been 1000-1 Shaun Micheel 1000-1 John Daly 1000-1