Quite reasonably, that led many to question whether or not an inflammatory article about American golf fans, written by Willett's brother and widely shared this week, had forced Darren Clarke into leaving him out so as to avoid any hostility on the first tee, on the first morning, of his first Ryder Cup.
Jimmy Walker and Zach Johnson will be playing together for the first time, going against Sergio Garcia and Martin Kaymer.
On Thursday, Team Europe members Henrik Stenson, Justin Rose, Andy Sullivan and McIlroy were playing a practice match at Hazeltine National Golf Club in Chaska, Minnesota, in preparation for the upcoming 2016 Ryder Cup, which kicks off Friday.
PGA Championship victor Jimmy Walker and Zach Johnson came from one down after 11 holes to beat Spaniard Sergio Garcia and Germany's Martin Kaymer 4&2 before Phil Mickelson and Rickie Fowler delivered the most surprising point of the morning for the Americans.
Westwood and Pieters were in the final match against US Open champion Dustin Johnson and Matt Kuchar and Clarke insisted it had not been a last-minute decision.
"It's a good start", USA captain Davis Love III told reporters after a chilly, overcast morning at Hazeltine gave way to bright afternoon sunshine. "So I would still tell them the same thing, you're a great team, let's go out there and have some fun, play your game, don't get in your own way".
Justin Rose will hit the first shot of the 41st Ryder Cup. And Thomas Pieters, this is his first Ryder Cup.
Kevin De Bruyne ruled out for up to a month
Despite Aguero scoring 11 times in six games he played this season, Guardiola believes the striker still has a lot more to offer.
Points: Europe needs 14 points to retain the cup. "They are ready to go".
Stenson said: "We played a match against Andy and Rory and they had a putt and Andy didn't make it, and they tried again to get the right line".
"It's very flattering to Team Europe that the U.S. have put this task force together and are trying to replicate what we've done", he said. "I have no worries about Danny whatsoever, mentally or otherwise".
"It's been pretty tricky for me to get back on and fully focus these last few hours, especially this morning", Willett told reporters on Thursday (Friday NZ Time). "His golf game is good". He wants to play. "I was disappointed in what he wrote and obviously it put a bit of a downer on my first Ryder Cup for the last couple of days", he said. He said the comment was a bit misconstrued because of the context of his conversation.
Mickelson will match Nick Faldo with the most appearances in Ryder Cup history when he tees off in his 11th, with "Lefty" having done his in a row without being a captain's pick.
The same format will be in play Saturday, with 12 singles matches Sunday for a total of 28 points.