The flag at half-staff over Hazeltine National was enough to take the edge off the Ryder Cup.

Arnold Palmer occupied everyone's thoughts on Monday.

"There's a hole in the game that can't be filled," Phil Mickelson said.

Tributes poured in for Palmer, who died Sunday at age 87. Even as European players arrived from an overnight flight out of Heathrow Airport, any conversation about the Ryder Cup was secondary to their thoughts on the King.

"The legacy he leaves behind is very important," Martin Kaymer said. "He inspired millions of people. That's what we as humans should try to do."

Alastair Johnston, the CEO of Arnold Palmer Enterprises, said Palmer had gone to Pittsburgh for a heart procedure in a bid to improve "the quality of life he was severely losing." The surgery was to be Monday morning. He said his condition deteriorated over the last few days.

A private funeral in Latrobe, Pennsylvania, was scheduled for later in the week. Johnston said that would be for "pure family, direct relationships." He said a public ceremony to commemorate Palmer's life would be held at 11 a.m. on Oct. 4 at St. Vincent College.

Johnston said Palmer would not have wanted to encroach on a week in golf as big as the Ryder Cup, though that proved difficult.

And the Ryder Cup made it clear it did not want to go on without Palmer.

PGA of America President Derek Sprague said there would a video tribute and a moment of silence before the high-charged matches begin Friday. He also said players would pay homage to Palmer, though details have not been decided.

"It was tough waking up this morning and starting over," U.S. captain Davis Love III said. "I know everybody on our team was just kind of crushed last night. ... This is a big blow for golf, but we knew it was coming, unfortunately, since maybe even before the Bay Hill tournament this year when we saw him. His legacy will live on forever, especially through the Ryder Cup."

The Ryder Cup was but a small part of Palmer's contributions to golf and sport. He played on six teams, all of them American victories during a time when they faced a Britain & Ireland squad that was overmatched. Palmer holds the U.S. record for most matches won (22), and in 1963 at East Lake he holds the distinction as being the last Ryder Cup playing captain. Palmer went 4-2 that year.

Europe has won the last three times in the Ryder Cup, and tension typically runs high as soon as its players arrive at the golf course.

Momentum was building toward the start of the week when Rory McIlroy rallied over the final holes to beat Ryan Moore in a playoff and win the Tour Championship and the FedEx Cup. Love was at Hazeltine preparing to tape a segment to be played at halftime of the NFL game announcing his final captain's pick (Moore). His son texted him with the news of Palmer's death, which changed everything.

"A bomb of that magnitude goes on in the golfing world ... it has ripples," Zach Johnson said.

How much does it alter the rest of the week?

Love and European captain Darren Clarke said they would alter their speeches at the opening ceremony Thursday.

"It's almost like we are all dealing with the loss of a family member," Love said. "Arnold is going to want us to put this behind us and go play, and it's going to be tough to do. But we are definitely going to draw inspiration from his spirits. We already had pictures of him in our locker room and team room, and we'll add a few more. He'll be with us forever."

Clarke said he was at Heathrow with some of his players on Sunday night, celebrating McIlroy's victory at East Lake, when they learned of Palmer's death.

"What I was going to say to my players I'm still going to say," Clarke said. "But obviously with the passing of the King, it's a slightly different perspective on the whole thing now. He will be missed. He was a lot of those guys' hero, as well."

Love said he found himself crying in quiet moments at the thought of Palmer, and he wasn't alone.

Fred Couples called Golf Channel on Sunday night and after one brief comment was sobbing so uncontrollably that he had to hang up. Curtis Strange, a two-time U.S. Open champion who played college golf at Wake Forest — Palmer's alma mater — also choked up talking about him and said he would wait to comment.

Love said Palmer's family has created a logo mentioning "Arnie's Army" that will be used as buttons for spectators and pins for the players. Those will be available to Americans and Europeans. He said any tributes would be done jointly.

"We've agreed that we're going to do the right thing for the game, and certainly this one for the Palmer family," Love said. "But both of our teams want to honor the Palmer legacy in the same way. I think you'll see us all honoring him all week."