GOLF

AUGUSTA, Ga. (AP) — Dustin Johnson has withdrawn from the Masters after injuring his lower back in a fall at the home he was renting for the week.

The world's No. 1-ranked player arrived at Augusta National on quite a roll, having won his last three starts.

But he never took a shot at the first major championship of the year.

Johnson walked to the first hole as if he was going to play in the final group of the day, but changed his mind at the last possible moment. Bubba Watson and Jimmy Walker teed off while Johnson sauntered back to the clubhouse, a stunning start to the tournament.

His Masters was over before it ever began.

Johnson was injured late Wednesday afternoon when he took what his agent described as a "serious" fall down a staircase.

BASEBALL

COLUMBIA, S.C. (AP) — Of course he did.

Tim Tebow hit a home run in his first official at-bat as a New York Mets minor leaguer, a charmed start for a popular yet polarizing athlete who seems to have a knack for these remarkable moments.

Playing a sport where many thought he didn't even belong in the batter's box, the former NFL quarterback and Heisman Trophy winner launched a two-run drive for the Columbia Fireflies in a Class A South Atlantic League game against Augusta. It was his only hit in five plate appearances.

"All of my sports experiences helped me for moments like that," Tebow said.

With a 15 mph wind blowing out, Tebow hit a shot just over the 372-foot sign in left-center field. He stopped at second base, thinking it was a double — but the ball hit a railing above the fence at the Bojangles Berm, and an umpire twirled his hand to indicate it was a homer.

PHOENIX (AP) — The Arizona Diamondbacks are following the Colorado Rockies and adding a humidor to store baseballs.

Diamondbacks President and CEO Derrick Hall told Arizona Sports 98.7 FM that the team had been considering it for some time and hopes to have one installed in about a month.

Hall said the team asked former Diamondbacks pitchers what they liked and didn't like about pitching at Chase Field. Most said gripping the baseball in Arizona's hot, dry air was the biggest issue.

The Rockies installed a humidor in 2002 to combat the effect Denver's high altitude has on the baseballs. Colorado is the only team in Major League Baseball to use a humidor.

HOCKEY

If another labor war is brewing for the NHL, Jonathan Toews won't be caught off-guard.

The Chicago Blackhawks captain shrugged when asked this past week about the bad, old days, like the lockout that wiped out the 2004-05 season and the delayed beginning of the 2012-13 season not all that long ago.

"Wouldn't be surprised," he said. "Can't say anyone should be surprised at this point."

The NHL announcement Monday that it won't participate in the 2018 Winter Olympics in South Korea next February shattered the harmony that appeared to be building after the return of the World Cup last year. To many players, it also seemed like an odd choice with the NHL adding games in Europe and making distinct efforts to gain a foothold in China, site of the next Winter Games in 2022.

While Olympic participation isn't an issue central enough to all 700-plus players to trigger a work stoppage as early as 2020, frustration over how the situation was handled has led many to wonder if the next collective bargaining negotiations will take an ugly turn.

IAAF

Defending Olympic and London marathon champion Jemima Sumgong has failed a drug test, the IAAF confirmed.

The sport's governing body says Sumgong "tested positive for EPO following a no-notice test conducted by the IAAF in Kenya."

Sumgong was the points leader in the World Marathon Majors series and was in line to receive a $250,000 bonus when the two-year cycle is completed in Boston on April 17. The series said it won't name a women's winner until doping officials have resolved her case.

WMM general manager Tim Hadzima said the series is distressed to learn of the reports but that, "if true, they indicate that we are gaining ground in our long-standing fight against doping."

The World Marathon Majors awards prizes to runners with the top finishes over six of the most prestigious annual marathons, plus the Olympics and world championships.