Rory McIlroy irked after Americans celebrate Ryder Cup win on 18th ...

GUIDONIA MONTECELIO, Italy -- European star Rory McIlroy had to be ushered into a car by teammate Shane Lowry during a heated argument in the parking lot of Marco Simone Golf Club on Saturday after McIlroy and Matt Fitzpatrick lost their Ryder Cup match to Patrick Cantlay and Wyndham Clark on the 18th hole.

NBC footage showed McIlroy screaming at someone, while caddie Jim "Bones" Mackay was standing close by. McIlroy shouted: "This can't happen. This can't happen. It's a f---ing disgrace." Mackay is American player Justin Thomas' caddie.

The incident in the parking lot likely spilled over from the U.S. team's celebration on the 18th green. A British media report on Saturday suggested that the U.S. team was fractured, and that Cantlay was one of the reasons because of his displeasure with American players not being paid to compete in the Ryder Cup. The report said Cantlay wasn't wearing a team-issued hat in protest, which he denied.

Many European fans mocked Cantlay during Saturday afternoon's match by waving their hats at him. Cantlay made birdies on three consecutive holes to help defeat McIlroy and Fitzpatrick, including a 43-footer on the 18th hole to win the match.

After Cantlay made the final putt, he pretended to tip a hat to the crowd. Other American players, caddies and team members waved their hats to European fans as well.

"Patrick made three great putts at the end to seal the deal, so hats off to them," McIlroy said after the match. "They played a great match, and yeah, I mean, a few scenes there on 18 and just fuel for the fire tomorrow."

Joe LaCava, who caddies for Cantlay, waved his hat from the green. McIlroy was preparing to putt and asked LaCava to move out of his way. TV replays showed LaCava start to walk away, but then turn back and say something else to McIlroy.

"Obviously, I was there on 18," European team captain Luke Donald said. "I saw it unfold when Patrick made that putt. Joe was waving his hat. Obviously, there was some hat-waving going on throughout the day from the crowd for our players. Talked to Rory. He politely asked Joe to move aside. He was in his line of vision. He stood there and didn't move for a while and continued to wave the hat, so I think Rory was upset about that."

Donald said he hadn't seen video of the incident in the parking lot.

"We love this event because of the passion, but we want to do it the right way," Donald said. "Obviously, Rory felt like the line was crossed on the 18th green. Again, I will address it with him when I see him. I wasn't there personally in the car park, but when I get back I will talk with him."

LaCava had words with European players Shane Lowry and Justin Rose on the 18th green as well. Rose and Cantlay will play each other in the third singles match at 5:59 a.m. ET.

After the match, Cantlay said he didn't see what happened on the 18th green.

"I was too busy letting out all the emotion that built up over the day," Cantlay said. "I didn't get a good look at it."

U.S. team captain Zach Johnson said during a news conference that the situation was "diffused after the match," and he was told "it's good."

LaCava moved from Tiger Woods' bag to Cantlay's in early May. He spent 20 years on Fred Couples' bag and worked with Dustin Johnson for four years. Woods hired LaCava in 2011 after splitting with longtime caddie Steve Williams. LaCava helped Woods capture his last Masters victory in 2019.