Hopefully, we can build a lot off this small amount of momentum we've got going," the world number five said.
Europe need only four points from Sunday's 12 singles but Cantlay referenced the European comeback in 2012 at Medinah when they hit back from 10-6 down to snatch victory.
"I saw it unfold when Patrick made that putt, Joe was waving his hat," he said.
U.S. captain Johnson said he was aware of an incident but was told McIlroy and LaCava were "all good".
"You see passion and emotion in the Ryder Cup and I don't think it's anything more than that," he said.
Persons:
Ryder, Marco Simone Golf, USA's Patrick Cantlay, Carl Recine, Patrick Cantlay, Marco Simone, Wyndham Clark, Cantlay, Rory McIlroy, Matt Fitzpatrick, caddies, McIlroy, Fitzpatrick, Cantlay's, Joe LaCava, we've, Wyndham we're, Luke Donald's, Zach Johnson's, Captain Donald, Patrick, Joe, Rory, Johnson, LaCava, Martyn Herman, Ed Osmond
Organizations:
Country Club, REUTERS, Rights, Ryder, American, Thomson
Locations:
Rome, Italy, Europe, Medinah, Medina, Luke Donald's Europe