Top-level golf continues its return from its coronavirus shutdown Thursday with the US PGA Tour's RBC Heritage behind closed doors at Hilton Head.

AFP Sport looks at three talking points after golf's successful resumption at last week's Charles Schwab Challenge, won by Daniel Berger.

For the first time in almost a year world number one Rory McIlroy will tee up on Thursday in South Carolina without the momentum of a top-five finish behind him.

The Northern Irishman's final-round 74 at Colonial on Sunday, including a disastrous front-nine 41, saw him finish T32 to break a US PGA Tour consecutive top-five streak going all the way back to August 2019 when he finished T19 at the BMW Championship.

McIlroy is still the bookmakers' favourite for the second PGA Tour event after the three-month coronavirus hiatus, though it will again be almost impossible to pick who will come out on top.

As at the Charles Schwab, the world's top five will all play in a field that features no fewer than 114 PGA Tour winners in an elite, 154-player field.

Wayward: World number one Rory McIlroy finished outside the top five for the first time since August last year at Colonial
Wayward: World number one Rory McIlroy finished outside the top five for the first time since August last year at Colonial GETTY IMAGES NORTH AMERICA / TOM PENNINGTON

Bryson DeChambeau's post-quarantine, bulked-up body drew plenty of comment at Colonial Country Club, but the transformation paid off for the maverick American who pocketed a cheque for $367,000 after finishing a stroke behind Berger.

Remarks about world number 12 DeChambeau beefy physique turned to gasps as he launched drives into uncharted territory.

"I've put on about 20 pounds (9kg) (during shutdown) and about 45 pounds (20kg) in the last nine months," said the 26-year-old.

"My ultimate goal is to get as strong as I can, applying some force and speed to the swing to see what it can handle."

DeChambeau led the field in driving distance, often bombing 350 yard-plus (320 metres) monsters.

That prompted a call from Colin Montgomerie for "tournament balls for professionals" to limit tour players.

"To see him carrying 330 yards in the air, this is getting unreal," said Montgomerie on BBC Radio.

A bulked-up Bryson DeChambeau during the final round of the Charles Schwab Challenge
A bulked-up Bryson DeChambeau during the final round of the Charles Schwab Challenge GETTY IMAGES NORTH AMERICA / Ron Jenkins

"Something has to be done or these classic courses cannot be used," said the 56-year-old Scot, who won the European Tour's Order of Merit eight times.

"There were only four holes on which Bryson was more than 100 yards away for his approach. It's now brute force and a sand wedge."

Berger's win on Sunday saw the American rocket to 31st in the world from 107th.

While it was a well-earned reward for beating a star-stacked field and battling back from a career-threatening wrist injury, the decision to unfreeze the Official Golf World Rankings has left a bitter taste for some.

The European Tour is unable to restart until July and the Asian Tour will be idle until mid-September, meaning US-based players have an unfair advantage.

Former number one Lee Westwood has dropped a couple of places to 33rd in the new rankings released Monday, while fellow Englishman Eddie Pepperell was the biggest casualty in the top 100, falling six to 71st while watching at home on TV.

"By the time I restart I'm going to be outside the top 100 and 80 yards behind Bryson (DeChambeau)," tweeted Pepperell.

Daniel Berger leapt from 107th to 31st in the world rankings with his win at Colonial on Sunday
Daniel Berger leapt from 107th to 31st in the world rankings with his win at Colonial on Sunday GETTY IMAGES NORTH AMERICA / TOM PENNINGTON

-- Official World Golf Rankings after Charles Schwab Challenge

1. Rory McIlroy (NIR) 9.35

2. Jon Rahm (ESP) 8.35

3. Justin Thomas (USA) 7.48 (+1)

4. Brooks Koepka (USA) 7.45 (-1)

5. Dustin Johnson (USA) 6.31

6. Patrick Reed (USA) 6.03 (+1)

7. Patrick Cantlay (USA) 5.90

8. Adam Scott (AUS) 5.89 (-2)

9. Webb Simpson (USA) 5.74

10. Xander Schauffele (USA) 5.67 (+2)

11. Tommy Fleetwood (ENG) 5.49 (-1)

12. Bryson DeChambeau (USA) 5.34 (+1)

13. Tiger Woods (USA) 5.32 (-2)

14. Justin Rose (ENG) 5.22

15. Marc Leishman (AUS) 4.73

16. Tony Finau (USA) 4.61

17. Gary Woodland (USA) 4.52 (+1)

18. Matt Kuchar (USA) 4.36 (-1)

19. Louis Oosthuizen (RSA) 4.29

20. Tyrrell Hatton (ENG) 4.26 (+1)

Selected

31. Daniel Berger (USA) (+76)