A strong post-major field tees off Thursday at Colonial Country Club, with three of the world's top 10 players scheduled to compete at the 2021 Charles Schwab Challenge.

William Hill Sportsbook lists Jordan Spieth as the 10-1 favorite in its latest 2021 Charles Schwab Challenge odds, and he is followed by Justin Thomas (12-1), Collin Morikawa (14-1) and defending champion Daniel Berger (16-1).

Before you lock in any 2021 Charles Schwab Challenge picks or PGA Tour predictions, you really need to see who golf insider Sal Johnson is backing.

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

Before Phil Mickelson shocked the golf world last week at Kiawah Island, the golf guru made it a point to include Louis Oosthuizen among his contenders. Johnson told SportsLine that Oosthuizen excels on links-style tracks like the Ocean Course and said he is  "always a good pick in majors." 

The South African came in as a 60-1 long shot but was right in the middle of the action all weekend and went 4 under to tie for second. 

He also has an eye for which players can capitalize on momentum. Before Hideki Matsuyama won the Masters last month, Johnson made special mention of Spieth, Xander Schauffele and Will Zalatoris as golfers to watch. 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 Charles Schwab Challenge picks, and they will surprise you.

Shockingly, the golf expert is slightly fading Thomas, even though he comes in as one of the top choices of oddsmakers! The world's No. 2 player missed the cut last week at the PGA (just barely), and that could be attributed to a course that gave many top players fits. But the 28-year-old hasn't played all that well since winning the Players, so Johnson is looking at several other players as better options.

Among his options, Johnson is touting a long shot who comes in at around 50-1 odds! Bigger hitters who can putt well excel at Colonial, and this player fits the bill. He has played well in this event before, and he could pull off a stunning victory in the 2021 Charles Schwab Challenge. Anyone who backs this underdog could cash in HUGE.

Who wins the 2021 Charles Schwab Challenge? Where do Jordan Spieth and Daniel Berger finish? And which MONSTER long shot is a MUST-BACK? ... Join SportsLine now to see Sal Johnson's full leaderboard and picks for the 2021 Charles Schwab Challenge, all from the insider who has a strong feel for when these players are in line for a big week!