ST. LOUIS — Tiger Woods and Phil Mickelson used to be seen as flip sides of the same generation. Woods was a two-seat Lamborghini, built for performance. He stood out from the crowd and left little room for others. Mickelson was a Subaru S.U.V., built for crowds. He was bulky and could accommodate everybody.
But those earlier versions, of Woods and Mickelson in their 20s and 30s, have given way in middle age to models that are more similar than not. Mickelson, 48, has turned himself into a sleeker machine who nosed out a player nearly half his age, Justin Thomas, the defending champion of the P.G.A. Championship, to win a World Golf Championships event in Mexico City in March for his 43rd PGA Tour victory — and his first in four years.
And Woods, 42, has become less isolated and more welcoming. The steely focus that made him so intimidating in his heyday is still there, but after the last putt drops, he is quick to smile and socialize with other players. After five years spent battling debilitating back pain that required four surgeries, Woods described himself on Tuesday as “very blessed” and said, “It’s a dream come true” to simply be back playing tournament golf.
“He’s more talkative,” Thomas said. “He’s enjoying himself more. He’s obviously still competitive and wants to kill us when he’s out there, but it definitely is a different Tiger than I watched on TV growing up.”
Fans who flock to Bellerive Country Club, the site of this week’s 100th P.G.A. Championship, to watch Woods and Mickelson go at each other like the St. Louis Cardinals and the Chicago Cubs are in for a surprise. The thaw that was evident at the Masters in April — when Woods and Mickelson, the best two golfers of their era, played a practice round together — has warmed into a full-fledged partnership.
“We’re both kind of realizing that we can get a lot more done together than we can on our own,” Mickelson said. “We’re better together than apart.”
An at-odds couple no more, they are completing details for a high-stakes match in Las Vegas over Thanksgiving weekend.
And before that, they expect to be a part of the United States team that will take on Europe in next month’s Ryder Cup in Paris. Each is motivated to finish well here to secure a playing berth, either on points or as a captain’s pick. Woods has committed to the team as an assistant to the United States captain, Jim Furyk.
Woods was the top-ranked player in the world and Mickelson was No. 2 the last time they were in the field for an event at Bellerive. It was 2001, and the event ended up being canceled because of the Sept. 11 terrorist attacks. In those days, Woods and Mickelson seemed so fundamentally different that, Thomas said: “You don’t choose both. You choose one or the other.”
Mickelson, a short-game maestro with an easy accessibility to the fans, won his first PGA Tour event while still an amateur and had nine victories when Woods turned pro in 1996. Woods, a power hitter whose early interactions with the public were mostly limited to when he hit his ball into the crowd, won the 1997 Masters, his first major start as a pro, in a rout. Over the next decade, he dominated golf as perhaps no athlete has ruled any other sport, accruing eight of his 14 major titles before Mickelson won the 2004 Masters for the first of his five major victories.
The millennials making their mark on golf now — players like Thomas, 25; Jordan Spieth, 25; and Rory McIlroy, 29 — grew up wanting to be like Woods. “It’s like any 8-year-old kid; right now, he probably wants to cheer for the Warriors,” Thomas said, referring to the team that has won three of the N.B.A.’s past four championships. His appreciation for Mickelson would come much later, once he was on the tour and saw his strengths up close.
“I really, really respect him, and I really, really respect what he’s doing now,” Thomas said. “I think people forget that a lot, that he’s playing at a very high level very often at 48 years old.”
As a youngster, Spieth was skeptical of Mickelson’s sunny demeanor and constant good cheer around the fans. “He’s real, but he’s wired differently than I am, which is why I thought he was fake,” Spieth said.
“I really thought there’s no way this guy can be that way — smile and give the thumbs up — all the time,” Spieth continued, adding, “And then you start to really see how he is when no one’s looking, and he’s the exact same person.”
Woods and Mickelson don’t have the same wiring, either. “They’re different people,” Spieth said.
But as Woods became a parent — and split custody after his 2010 divorce — his daughter, Sam Alexis, 11, and his son, Charlie Axel, 9, helped him find a lower gear in which to idle.
“When I play a bad round, I fester a little bit, but now I go home and I’ll be with the kids or they want to talk and FaceTime,” Woods said, adding, “When it’s time to play, it’s time to play, and when it’s not, it’s just different.”
Mickelson has striven to put his family ahead of golf: Last year, he bypassed the United States Open, the only major he has not won, to attend the high school graduation of his firstborn, Amanda.
A few of Mickelson’s playing colleagues immediately thought of Amanda and her two siblings, Sophia, 16, and Evan, 15, when they watched him dancing enthusiastically but inexpertly in a new commercial for his line of golf dress shirts. “We were saying, like, what are his kids’ friends going to say when they go back to school?” McIlroy said with a laugh.
Mickelson said his children were cool with it. “They helped me pick out the moves,” he said, adding, “I think it’s fun to laugh at yourself.”
Woods’s humor came through last week during the stilted dance that is his postround scrum with reporters. After his Saturday round at the World Golf Championships event in Ohio, he stepped to the podium wiping perspiration from his face.
“You are sweating like Martha Stewart getting a stock tip,” Michael Collins of ESPN joked. Without skipping a beat, Woods replied, “Before or after?”
The next day, after a disappointing tie for 31st, Woods talked about hitting a few pulls off the tee and a few blocks. “I had them both going this week,” he said with a smile. Asked if he needed a day off, he joked, “I’m done pretty early today so I’ll have this afternoon off.”
It would have been hard to imagine the Woods of a decade ago poking fun at his bad shots or an early Sunday finish. It would have been just as hard to picture Mickelson playing in the event that Woods hosts every December. But last week, Mickelson said he was seriously considering adding the Bahamas tournament to his schedule.
When a reporter relayed the news to Woods, he beamed. “Oh, he didn’t say that to me,” he said. “That made me feel better.”