Washington (AFP) - Five-time Major winner Phil Mickelson and Jordan Spieth, the 2015 US Masters champion who bungled a repeat bid, begin play on Thursday at the PGA Houston Open with the Masters looming next week.
Also in the field a week before the year's first Major championship at Augusta National are England's Justin Rose, Australia's Adam Scott, 2016 British Open champion Henrik Stenson of Sweden, WGC Match Play runners-up Jon Rahm of Spain and 2016 PGA Championship winner Jimmy Walker of the United States.
World No. 1 Dustin Johnson withdrew from the event on Monday, citing fatigue after winning last week's WGC Match Play title in Austin, Texas.
The reigning US Open champion has won his past three events and is a heavy Masters favorite.
Johnson was in the hunt last year before a double bogey at 17 on Sunday doomed his Masters bid.
Spieth had been a runaway leader before back-to-back bogeys and a double splashdown into Rae's Creek for a quadruple bogey at the par-3 12th ruined his round, allowing England's Danny Willett take the title.
Mickelson, a three-time Masters champion who finished second to Stenson at last year's British Open, could become the oldest Masters winner next week at age 46.
Jack Nicklaus was two months past 46 when he set the mark by winning in 1986.
"Lefty" will be just over two months shy of 47 when he tees off next week.
"I almost always play the week before a Major because if I take it off, I often feel a little rusty at the start," said Mickelson, who has 42 PGA titles but none since taking the 2013 British Open at Muirfield.
It doesn't hurt that the Golf Club of Houston does its best to emulate conditions players will face next week at Augusta National.
"It's tremendous," Mickelson said. "The greens are fast. The fairways are perfect and tight. They even mowed the grain... in the fairways just like Augusta does. There is no rough. The first cut is like Augusta.
"I like playing in a tournament that's similar to what we'll be playing. It's a great place to get ready for next week."
Stenson skipped the WGC event to play in Houston so he could make an early practice trip to Augusta, then compete just before chasing a green jacket.
"Scheduling is a big part of it, given that I want to play the week before Augusta," Stenson said.
"I've played in the Middle East, I've had a couple weeks off and then I need to pick up some pace."
Rahm, 22, had never played Augusta National until practice rounds earlier this month, but he thinks he has the game to be among the contenders there next week.
"Certainly I do feel like I belong there, that I belong where I am right now and that I compete to win," Rahm said.
Rahm played 108 holes last week at the WGC Match Play tournament but wanted to avoid arriving too early at Augusta National and dwelling upon his debut next week.
He took off the week before last year's US and British Opens and shared 23rd at Oakmont and 59th at Royal Troon in his first major starts.
"For the British Open, I think I would have benefited from playing the week before," Rahm said.
"That's why I want to play this week. Last week I played good. Why wouldn't I keep that level of play up?"
Rahm has opened the year well, winning at Torrey Pines and sharing third at the WGC Mexico event before losing the WGC Match Play final to Johnson.