NEW YORK — Ryan Howard thought about the World Series and his eyes widened.

‘‘Between Yankee Stadium and Philly, it’s going to be, I would have to say, probably one of the rowdiest World Series — just between the fans,’’ he said.

Sure will be if Howard and Alex Rodriguez start teeing off in their high-profile slugger showdown.

For the first time in 20 years, the World Series will feature a pair of former major league home run champions when it opens, weather permitting, on Wednesday night.

No player in the major leagues has been scrutinized more than A-Rod, a postseason star following a scandalous spring training that include a steroid admission and hip surgery.

And Howard has carried the defending champion Philadelphia Phillies every bit as much as Rodriguez has propelled the Yankees to their first Series appearance since 2003 — and the first of his career.

‘‘Ryan, along with his power, he’s also become a great hitter,’’ Rodriguez said Tuesday. ‘‘And that’s bad news for the National League and bad news for us.’’

The 34-year-old Rodriguez already has succeeded Reggie Jackson as the favorite Yankees target of wannabe amateur psychologists, who try to analyze past playoff flops and his relationships with Madonna last year and Kate Hudson this season. Now he wants to follow Mr. October as a champion.

A three-time AL MVP, he entered the first round against Minnesota hitting .136 (8 for 59) in the postseason dating to 2004 and was hitless in 18 consecutive playoff at-bats with runners in scoring position.

What a change.

He led the Yankees with a .438 average, five homers and 12 RBIs in the victories over the Twins and Los Angeles Angels, hitting tying home runs in the seventh, ninth and 11th innings.

‘‘I think everyone is looking for a profound answer, and I don’t have one,’’ he said, sitting behind a table in Yankee Stadium’s Great Hall as baseball adopted an NFL-style approach to Series publicity for the first time.

‘‘I think at the end of the day, I’m content. I’m happy, both on and off the field,’’ Rodriguez said. ‘‘I think I’ve cut out a lot of the fat, or unnecessary distractions.’’

The 29-year-old Howard also needed a winding, if less notorious, path to postseason success. He had only one RBI in reach of his first two playoff series while hitting .217 (5 for 23), then batted .300 with two RBIs against the Los Angeles Dodgers in last year’s NL championship series. He then hit three homers and drove in six runs in leading the Phillies over the Tampa Bay Rays for Philadelphia’s second-ever title.

And this year, he’s batted .355 with 14 RBIs in the playoffs against the Rockies and Dodgers.

‘‘I think that our approaches this postseason, as opposed to be previous postseasons, are a lot better,’’ Howard said. ‘‘I think both of us are a lot more patient, both of us are a lot more relaxed, it looks like. You know, I’m going out there just having fun. It looks like that’s what he’s doing, as well.’’

Both teams worked out Tuesday in the mist of $1.5 billion new Yankee Stadium, where two freshly painted logos were in foul territory in honor of the ballpark’s first World Series. Still standing across the street, covered in black mesh as if a ghost, is its 86-year-old predecessor, awaiting demolition after hosting a record 100 Series games.

CC Sabathia, 3-0 with a 1.19 ERA in his first postseason with the Yankees, starts for New York against former Cleveland teammate Cliff Lee, 2-0 with an 0.74 ERA for the Phillies. It’s a rematch of the April 16 ballpark opener, won by the Indians 10-2.

This will be only the second Series with two former season home runs leaders since 1975’s faceoff between Cincinnati’s Johnny Bench and Boston’s Carl Yastrzemski, according to STATS LLC. The other was in 1989’s Earthquake Series, when Oakland’s Bash Brothers of Jose Canseco and Mark McGwire swept San Francisco and Kevin Mitchell.

Rodriguez had a remarkable season, especially after missing the first month following March 9 surgery to repair torn cartilage in his right hip. He homered on his first and last swings of the regular season, reaching 30 homers and 100 RBIs for the 12th consecutive year by hitting a three-run homer and a grand slam in a single inning at Tampa Bay.

He said two close friends — he didn’t identify them — took him to breakfast at spring training after he admitted using steroids from 2001-3, and they told him he had to change. He called it ‘‘tough love.’’

Since then, he’s eliminated many of the advisers and outside experts who made him more of a business than a ballplayer. He said he also stopped obsessing on putting up big statistics and beating himself up when he didn’t. His only goal was the Yankees’ 27th title, their first since 2000.

‘‘For me it was obvious in spring training I hit rock bottom,’’ he said. ‘‘You can only hit your head against the wall so many times, you know, before you figure out there’s another way to get to the other side of the wall.’’

Rodriguez said sitting at the table reminded him of his spring training news conference, when he took heart that his teammates and Yankees staff sat near him ‘‘when a lot of people were running the other way.’’

Howard has managed to maintain himself as a player throughout, not a commodity. He’s paid attention to Rodriguez — for the baseball, not the business.

‘‘I’ve watched A-Rod and just tried to study guys like A-Rod, study like Manny, Albert,’’ he said, a reference to Manny Ramirez and Albert Pujols. ‘‘You don’t want to be known as just a slugger. You want to be known as a good hitter or a great hitter.’’

And this Series features two of them.