Entering Thursday's 2021 PGA Championship, perhaps no contender has a bigger question mark than Dustin Johnson. The No. 1 player in the world doesn't have a single top-10 finish in 2021 and was forced to withdraw from last week's AT&T Byron Nelson due to a knee injury. On the other hand, Johnson finished as the runner-up at the PGA Championship the last two years, joining Jack Nicklaus as the only golfers to do so. The PGA Championship 2021 will also be in his birthplace of South Carolina and Johnson is eagerly looking for his first home-state victory.

Kiawah Island Golf Resort's Ocean Course will play host to the 2021 PGA Championship field, which tees off Thursday at 7 a.m. ET. With his lack of recent success on tour, Johnson is listed at 18-1 at William Hill Sportsbook, putting him outside of the top five 2021 PGA Championship contenders. Rory McIlroy (11-1) tops the 2021 PGA Championships odds, followed by Justin Thomas (14-1) and Jon Rahm (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 knows what it takes to win on the tough major championship courses. He tabbed Brooks Koepka among his contenders before both of his back-to-back PGA Championship wins in 2018 and 2019. In 2020, he backed Dustin Johnson before he came up just shy, tying for the runner-up spot behind Collin Morikawa.

Before the 2018 PGA Championship, Johnson saw Koepka heating up and knew Bellerive was a course he could do well on. "The guy is healthy and on a run," Johnson said before Koepka held off Tiger Woods to win by two strokes.

Before they played Bethpage in 2019, Johnson was firmly behind Koepka again. "I really like him a lot this week," the golf expert told SportsLine. "He is playing well and this is a course he can attack and play well on." This time, he held off Dustin Johnson to win by two for his fourth major title.

The golf expert also 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.

Watch the 2021 PGA Championship beginning Thursday with Rounds 3-4 streaming live over the weekend on CBSSports.com, the CBS Sports App and Paramount+. Check out the updated PGA Championship schedule for how to watch the year's second major all week long.

Top 2021 PGA Championship expert picks

Shockingly, the golf expert is fading Bryson DeChambeau. He has the distance to dominate a course like this, but Johnson says he won't because the tour's bomber can't play in windy conditions. He has missed the cut twice and tied for 51st in his three British Opens, and his game went south on the weekend in Dallas when the weather turned. All 10 of his professional wins have come in near-perfect conditions. He also misses plenty of fairways (172nd in driving accuracy), so "this week will be miserable for Bryson," the golf guru told SportsLine.

On the other hand, Johnson knows how much the Wells Fargo win will mean to McIlroy's confidence. The Northern Irishman's struggles were well-documented, but he spent a month working on his swing after a missed cut at the Masters and seemed to feed off the fans at Quail Hollow. He was in contention nearly every week before the tour shut down last spring and now has momentum as he arrives at a course where he won by a record eight strokes in 2012. The 31-year-old is second on tour in driving distance (318.8) and 18th in total strokes gained.

The golf guru also knows Spieth comes in more confident than anyone and will be fired up to go after the grand slam. Spieith is No. 8 in the FedEex Cup standings and won the Valero Texas Open at the beginning of April. He followed that up with a third-place finish at the Masters and a ninth-place run at the AT&T Byron Nelson. He hasn't shot a round above 72 in his last three tournaments. However, he was cut earlier this season in four of his first seven tournaments and fired an 81 in the second round of the 2020 U.S. Open.

How to make 2021 PGA Championship predictions

This week, Johnson is touting a long shot who comes in at well over 50-1 odds. This player has plenty of experience on links-style courses and has been consistently competitive. He could pull off a stunning victory in the 2021 PGA Championship, 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 Jon Rahm and Dustin Johnson 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.

2021 PGA Championship field, odds, contenders

Rory McIlroy 11-1
Justin Thomas 14-1
Jon Rahm 14-1
Jordan Spieth 16-1
Bryson DeChambeau 16-1
Dustin Johnson 18-1
Xander Schauffele 22-1
Viktor Hovland 25-1
Daniel Berger 30-1
Collin Morikawa 30-1
Brooks Koepka 33-1
Hideki Matsuyama 33-1
Patrick Cantlay 35-1
Webb Simpson 35-1
Cameron Smith 35-1
Patrick Reed 35-1
Tony Finau 35-1
Scottie Scheffler 40-1
Sam Burns 40-1
Tyrrell Hatton 45-1
Will Zalatoris 50-1
Tommy Fleetwood 50-1
Paul Casey 50-1
Abraham Ancer 50-1
Matthew Fitzpatrick 55-1
Sung-Jae Im 60-1
Joaquin Niemann 60-1
Louis Oosthuizen 60-1
Marc Leishman 60-1
Justin Rose 66-1
Shane Lowry 66-1
Sergio Garcia 66-1
Corey Conners 66-1
Adam Scott 70-1
Keegan Bradley 70-1
Brian Harman 80-1
Gary Woodland 80-1
Max Homa 80-1
Matt Wallace 80-1
Garrick Higgo 80-1
Jason Day 80-1
Si-Woo Kim 80-1
Charl Schwarzel 90-1
Bubba Watson 90-1
Robert Macintyre 100-1
Jason Kokrak 100-1
Lee Westwood 100-1
Harris English 100-1
Matt Kuchar 100-1
Billy Horschel 125-1
Rickie Fowler 125-1
Cameron Tringale 125-1
Kyoung-Hoon Lee 125-1
Cameron Champ 125-1
Charley Hoffman 150-1
Branden Grace 150-1
Russell Henley 150-1
Christiaan Bezuidenhout 150-1
Kevin Na 150-1
Alex Noren 150-1
Matt Jones 150-1
Stewart Cink 150-1
Ian Poulter 150-1
Emiliano Grillo 150-1
Aaron Wise 150-1
Ryan Palmer 175-1
Chris Kirk 175-1
Francesco Molinari 200-1
Kevin Kisner 200-1
Cameron Davis 200-1
Martin Kaymer 200-1
Sebastian Munoz 200-1
Thomas Pieters 200-1
Harold Varner 200-1
Kevin Streelman 200-1
Victor Perez 200-1
Zach Johnson 200-1
Brendon Todd 200-1
Phil Mickelson 200-1
Carlos Ortiz 200-1
Joel Dahmen 250-1
Dylan Frittelli 250-1
Bernd Wiesberger 250-1
Brendan Steele 250-1
Henrik Stenson 250-1
John Catlin 250-1
Danny Willett 250-1
Talor Gooch 250-1
Sam Horsfield 250-1
Dean Burmester 250-1
Erik Van Rooyen 250-1
Lanto Griffin 250-1
Denny McCarthy 300-1
Harry Higgs 300-1
Thomas Detry 300-1
Antoine Rozner 300-1
Maverick McNealy 300-1
Martin Laird 300-1
Steve Stricker 300-1
Andy Sullivan 300-1
Tom Lewis 300-1
Tom Hoge 300-1
Mackenzie Hughes 300-1
Byeong Hun An 300-1
Adam Hadwin 300-1
Rasmus Hojgaard 300-1
Jazz Janewattananond 350-1
Jim Herman 400-1
Kalle Samooja 400-1
J.T. Poston 400-1
Brandon Stone 400-1
Padraig Harrington 400-1
George Coetzee 400-1
Sami Valimaki 400-1
Kurt Kitayama 400-1
Aaron Rai 400-1
Jimmy Walker 500-1
Rikuya Hoshino 500-1
Peter Malnati 500-1
Robert Streb 500-1
Brian Gay 500-1
Adam Long 500-1
Chan Kim 500-1
Hudson Swafford 500-1
Daniel Van Tonder 500-1
Richy Werenski 500-1
Takumi Kanaya 500-1
Jason Scrivener 500-1
Chez Reavie 500-1
Lucas Herbert 500-1
Brett Walker 500-1
Jason Dufner 500-1
Vijay Singh 1000-1
Y.E. Yang 1000-1
John Daly 1000-1
Brad Marek 2000-1
Sonny Skinner 2000-1
Peter Ballo 2000-1
Patrick Rada 2000-1
Greg Koch 2000-1
Alex Beach 2000-1
Stuart Smith 2000-1
Danny Balin 2000-1
Rich Beem 2000-1
Mark Geddes 2000-1
Rob Labritz 2000-1
Frank Bensel 2000-1
Omar Uresti 2000-1
Ben Polland 2000-1
Larkin Gross 2000-1
Derek Holmes 2000-1
Ben Cook 2000-1
Tim Pearce 2000-1
Joe Summerhays 2000-1
Shaun Micheel 2000-1
Tyler Collet 2000-1