Tiger Woods said practice sessions have been eerie.

Inside the clubhouse, locker No. 162 has his name on it, as if the U.S. Open champion is going to arrive any minute now and change into his steel-tipped golf shoes.

And out on the course, some 29 golfers keep looking over their shoulders. Wondering. Waiting. Asking why?

Stewart, who along with five others died in a plane crash on Monday, won't be here. And for the golfers trying to get on with their lives at what is usually a meaningful tournament, it has been very difficult to accept.

"No one really knows how to react because it was so sudden. It was a shock to everybody," said Tiger Woods, who said he told coach Butch Harmon, "'I almost feel like he is going to show up.' I just saw him the other day. It is hard to believe he is not going to be here."

The $5 million Tour Championship begins Thursday, but it will be unlike any other golf tournament.

In order for players to be able to attend a memorial service on Friday in Orlando, the tournament schedule has been altered. The 72-hole event will be divided into 27 holes each on Thursday and Saturday, with 18 holes to be played on Sunday. No golf will be played here on Friday.

There will also be a brief memorial service for Stewart on Thursday morning on the No. 1 tee at Champions Golf Club. Then the tournament will begin, Duffy Waldorf playing with a marker who is taking Stewart's spot in the field.

All of which makes for a very uncomfortable situation. Jeff Sluman was on the practice green, rolling putts at a cup, unaware if they were dropping -- and unconcerned.

"Golf is, I think if you talk to everybody ... it's a non-event," Sluman said. "I don't think there are any words that anybody can use to describe how bad everybody feels, the helplessness.

"It's very difficult being out here. It's difficult talking to you guys (media). All you can do is take one minute at a time, one step at a time. You're never going to make any sense of it. Nobody is that smart. I don't know what you do. I really don't."

Although the players were given the option of skipping Tuesday's pro-am, many of them showed up, practiced and played with amateur partners. "If you could tell me what else I should have done, I would have been open to the suggestions, but I didn't know what else I should do," said David Duval.

Nonetheless, the atmosphere has been lacking. Unlike the typical days leading up to a tournament with the top players in the world, the turnout was sparse, the mood somber. Golfers were on the course in body, but not spirit.

"It was almost eerie," Woods said. "And nobody was really asking for autographs or clamoring for pictures. It was just real quiet. Even on the range, nobody was talking. It was just silent out there. It was very eerie when we first started warming up."

Sluman said it would not have bothered him if the tournament had been canceled or postponed, but others had no problem with it being played.

"I think the tournament should go on," Woods said. "But obviously, it is not going to be an easy week for all of us. It's going to be a tough one. It is going to be a tough week."

Stewart, 42, was enjoying the best season of his 20-year career. He had won more than $2 million on the PGA Tour, and captured the AT&T Pebble Beach Pro-Am and the U.S. Open, his third major championship.

He was third on this year's money list with this week's Tour Championship and next week's American Express Invitational remaining on the schedule.

"There's not only a shroud over this tournament, but the rest of this year," said Brian Sullivan, who caddies for Jeff Maggert. "And what about next year's U.S. Open? That's going to be a very hollow event."

Sullivan was walking the front nine of the Champions course on Monday with Mike Hicks, Stewart's caddie who lept into his arms after making the winning 15-foot par putt at Pinehurst to capture the U.S. Open. They were trying to get a head start, learning the course. Stewart was to meet Hicks later Monday.

Hicks' cell phone rang as the walked off the ninth tee, and within a matter of moments he was hearing the news of Stewart's wayward flight that eventually crashed in South Dakota.

"From there, the pain turned into horror," Sullivan said. "We knew it was bad."

All that is left now are memories. Duval, who played on the U.S. Ryder Cup team last month with Stewart, was asked to recall his first meeting with Stewart.

"I think Payne is one of those people you seem like you have known forever," Duval said. "Just because he was so recognizable with his clothing and his hat. I think everybody thinks they have known him for a long time."

"Last week," said Sluman, "he looked over my shoulder as I was working on my game. He has his 10-year-old son Aaron there. We're warming up on Wednesday, getting ready to play the father-child tournament at Disney, laughing and having a good time. Then off and away he goes. It's the last time I saw him.

"That's a memory that is hard to forget, watching him ride off with his son to play golf."

Bob Harig, who covers golf for the St. Petersburg Times, writes a column every Tuesday for ESPN Golf Online.