Louis Oosthuizen leads the way at Royal St. George, with Jordan Spieth and Brian Harman a shot further back.
World No. 1 Jon Rahm is the bookmakers' favorite as he looks to win a second consecutive major.
Brady and Mickelson will play against Green Bay Packers QB Aaron Rodgers and 2020 U.S. Open champion Bryson DeChambeau for charity.
The Spaniard won his maiden major after shooting 4-under par in the final round at Torrey Pines on Sunday.
Russell Henley and Louis Oosthuizen lead the way at Torrey Pines, with Brooks Koepka and Jon Rahm two shots adrift.
The third major of the season gets underway at Torrey Pines on Thursday with Jon Rahm as the bookmakers' favorite.
The four-time major winner appeared to be clearly unimpressed by the reigning U.S. champion during a TV segment on Friday.
The PGA Championship's total purse was worth a combined $12 million, the most lucrative in the tournament's history.
Mickelson became the first player in over a decade to win a major tournament after starting with odds over 200-1.
Corey Conners is the bookmakers' favorite at 7-1 after taking a two-shot lead in the first round at Kiawah Island.
Canada's Corey Conners leads by two strokes after shooting a 5-under par 67 in the first round, with Brooks Koepka and Phil Mickelson two and three shots behind.
Rory McIlroy is the bookmakers' favorite to win the second major of the season, followed by Jordan Spieth and Jon Rahm.
The second major of the season gets underway on Thursday at Kiawah Island Golf Resort in South Carolina.
"It's nice to have a faithful rehab partner," Tiger Woods wrote on Instagram, showing his first photo since the February 23 crash.
Matsuyama became the first Japanese player to win The Masters after finishing one stroke clear of Will Zalatoris.
Justin Thomas, Phil Mickelson and Jack Nicklaus all wished the 15-time major winner a speedy recovery.
The 15-time major winner was involved in a single-vehicle crash 30 miles south of downtown Los Angeles on Tuesday.
The Los Angeles County Sheriff's Department announced on Tuesday that the golf star was involved in a "single vehicle roll-over traffic collision."
On Wednesday, the Scottish parliament will debate a motion on whether to probe Trump's financing of his two golf courses in Scotland.
The PGA of America stripped Trump National Golf Course in Bedminster of the 2022 PGA Championship following the Capitol attacks last week.
The opening round of at Augusta National was suspended after just 30 minutes because of lightning and torrential rain.
It wasn't even the first hole-in-one he's made all week. He made another on Monday and posted the video on Instagram.
First-round leader Justin Thomas tees off at 1:27 p.m. ET alongside 15-time major winner Tiger Woods.
Justin Thomas leads the U.S. Open by one shot after carding a 5-under 65 in the first round on Thursday.
Tiger Woods starts the first round of the U.S. Open at 8:07 a.m. ET on Thursday from tee No. 1 alongside Justin Thomas and Collin Morikawa.
The first round of the U.S. Open gets underway at 6:50 a.m. ET on September 17, with world No.1 Dustin Johnson set to hit his first tee shot shortly after 1 p.m. ET.