The reports of Rory McIlroy and Tiger Woods' deteriorating relationship came to life on Thursday at the PGA Championship as a frosty exchange between the pair was caught on camera.

As the two crossed paths at Valhalla, they didn't greet one another - let alone look in each other's direction - during the first day of the tournament.

At the time of writing, Woods is one-over-par through 10 holes while McIlroy is one-under through 11.

The interaction - or lack thereof - comes amid reports from Golf Digest that Woods and McIlroy's relationship has 'soured over the past six months' yet 'remains cordial'.

McIlroy resigned from his position on the PGA Tour board in November, though the Northern Irishman had looked set to return to that role in recent weeks as the organization continues its negotiations with LIV Golf.

However, the board reportedly voted against McIlroy's re-inclusion, and according to The Telegraph, Woods was one of the player-executives who voted 'no' on a McIlroy return. 

The board also comprises of Patrick Cantlay, Peter Malnati, Adam Scott and Jordan Spieth.

McIlroy acknowledged that 'old wounds had re-opened' in his failed reintegration to the board.

'It just got pretty complicated and pretty messy,' he said at the Wells Fargo Championship last week.

'With the way it happened it opened up some wounds and scar tissue from things that have happened before. And I think there was a subset of people on the board who were uncomfortable with me coming back on for some reason.'

Woods and McIlroy were known to be close friends but have differed in their stances on how the PGA should deal with the Saudi-backed LIV tour.

McIlroy was initially a hugely staunch critic of the league, but U-turned in April when he said the PGA needed to find a way to work with LIV, and that golf's current situation was 'not sustainable.'

Woods, meanwhile, has been less open to collaboration with LIV following the PGA's recent deal with the Strategic Sports Group.

'Financially, we don’t [need that] right now,' he said.

The monies that they have come to the table with and what we initially had agreed to in the framework agreement, those are all the same numbers. Anything beyond this is going to be obviously over and above. We’re in a great position right now.

McIlroy's appearance at the PGA Championship comes amid his divorce from his wife Erica Stoll, which was confirmed by his communications team earlier this week.

The pair had been married for seven years and share one daughter, Poppy.

McIlroy's communications team stressed his 'desire to ensure this difficult time is as respectful and amicable as possible.'