Smoltz will be added starter

The newest member of the Sox, John Smoltz, has the best postseason record in history - 15-4. (George Rizer/Globe Staff)

Twenty-three years have passed since John Smoltz made a walk like this, from behind a curtain and out to a dais, where a crisp white jersey lay next to a new cap. He was 18 then, a draft choice of the Detroit Tigers. He is 41 now, a future Hall of Fame pitcher with 20 years in the major leagues, all of them with the Atlanta Braves.

Yesterday, Smoltz led Red Sox general manager Theo Epstein to a podium, then let him pass and pick up the jersey. Epstein passed it to Smoltz.

"Very nice," Smoltz said, gazing at his new No. 29 as camera lights flashed off his gray suit. And with that, Smoltz sat down and officially became a member of the Boston Red Sox, team No. 2 in Year No. 21.

"Certainly there's that shock a little bit," Smoltz said. "But once you get up here, and you see the things . . .

"I've been here as a visiting player, and I can't even describe it. It's been, in the hardest of moments, the easiest transition that I've ever been a part of."

The Red Sox envision Smoltz - who closed games for four seasons - as a starter, and they will bring him into the rotation with a unique approach. Though Smoltz could be ready to pitch by April, the Red Sox have eased his recovery from shoulder surgery to ensure he will be at full health and in peak form for October, so he will not pitch until an undetermined date in midseason.

"I love their approach," Smoltz said. "Their approach is, 'We're going to slow you down and give us the best chance to win a championship. Whenever you're ready, you're ready.'

"That, to me, is the only hard part, but I can deal with that. If I have to slow down for the benefit of this long run, then it's worth it."

Smoltz is famous for his competitive nature and athletic ability; he often plays golf with Tiger Woods, who has called Smoltz the best golfer he has seen outside the PGA Tour. Smoltz has won more postseason games than any other pitcher, his 15-4 record and 2.65 ERA being primary reasons the Sox wanted him.

"We're looking at the big picture here," Epstein said. "The reason we acquired John Smoltz is to put him in a position to get back to 100 percent and dominate at the most important times of the year. For us, that works backwards from October."

The delay is necessary because Smoltz is coming off major shoulder surgery, which he underwent roughly seven months ago. It was the fifth surgery of Smoltz's career, which has seen him adjust his arm angle multiple times.

Before the surgery, Smoltz allowed the notion of retirement to creep into his mind. Afterward, though, he never contemplated walking away. He began strengthening his shoulder, sometimes for three hours a day.

He figured the Braves would work to re-sign him, but they showed only lukewarm interest. In November, his agent mailed a video to several teams Smoltz was interested in. One was the Red Sox.

The video showed Smoltz throwing from a bullpen and chucking spirals with a football. The Sox were interested enough to fly pitching coach John Farrell, trainer Mike Reinold, and vice president of player personnel Ben Cherington to Atlanta to watch Smoltz throw in December.

"They saw what they were getting," Smoltz said. "And they saw what I was capable of doing. That's a pretty impressive thing, even for a guy who's been playing 22 years."

Reinold put his hands on Smoltz's shoulder and was amazed at how far he had come since the surgery. Farrell told Epstein Smoltz was a "physical freak." If that session had come on the opening day of spring training, Epstein said, it would have been adequate.

When the Braves didn't match the Red Sox' interest, the sides began hammering out a one-year contract. Though he'll turn 42 in May, Smoltz said, "I don't see this as a one-year thing. Age is just a number."

Smoltz arrived in Boston Monday and attended the Celtics-Raptors game that night. His face was flashed on the Jumbotron, and the Garden erupted. "It blew me away," Smoltz said.

Smoltz has enjoyed playing as a visitor at Fenway Park, saying he fed off the enthusiasm of the fans. He is 2-0 with two saves at Fenway, and has not allowed an earned run in 20 2/3 innings there. That comfort made the change easier, even for someone leaving the place he called home.

"It caused me to be at my absolute best," Smoltz said. "This a great opportunity for fans that expect you to give your best. Words can't describe where I feel right now to put on the uniform."

Adam Kilgore can be reached at akilgore@globe.com