Much of the focus as baseball heads into the second half is on the possible suspensions of Alex Rodriguez, Ryan Braun and a handful of All-Stars implicated in the Biogenesis performance- enhancing drug scandal.

Puigmania, a Pirates revival and an impressive power show in Baltimore may shift the gaze back to the field, where there will be a lot to watch going down the regular-season stretch.

Fans who celebrated Mariano Rivera at every stop of a farewell tour should get to watch returning stars Derek Jeter, Chris Carpenter, A-Rod and even Manny Ramirez after a first half dominated by 20-somethings.

The American League won the All-Star game Tuesday night, getting home-field advantage in the World Series back after three years of NL dominance. Now the race is on to get there, and some underachieving preseason favorites are looking to make their moves.

Every playoff spot is legitimately up for grabs, with no team leading a division by more than six games. And the NL East, where Atlanta is up six on Washington, is the only place where the division leader is ahead by three games or more.

What to look for in the second half that begins Friday:

CLOCK IS TICKING

• The Washington Nationals need a healthy Bryce Harper to help them chase down Atlanta.

• The big-spending Dodgers are surging, 17-5 since June 22, thanks to the youthful exuberance of Yasiel Puig, with a smile to match that of the owner, Magic Johnson.

• The Blue Jays made the biggest offseason moves but NL Cy Young Award winner R.A. Dickey’s knuckleball has been mostly off-target and Toronto finds itself in last place in the AL East. But don’t count anyone out in what’s widely considered the toughest division in the majors.

• Pedro Alvarez and the Pittsburgh Pirates appear poised to put 20 years of misery behind, after two years of teasing fans by being in the hunt heading into the break only to fade down. With the Houston Astros now in the AL, the NL Central is one of the most competitive divisions.

Reds Manager Dusty Baker knew it would be a stiffer challenge this year.

“I figured it would be close, closer, because none of us have the Astros in our division that we were counting on — not to malign them — but they were in our division last year and every team kind of counted on beating them,” he said. “Now you’ve got to beat each other.”

• So far it’s only been California dreamin’ for Josh Hamilton in his first year in Los Angeles, even with Houston in the division. He’ll have to improve on his .224 average and .413 slugging percentage for the Angels to have a shot to overtake Yoenis Cespedes and the pesky Oakland A’s. Albert Pujols’ ballclub is 11 games back in the AL West and nine games behind for the wild card.

HOMER CRUSH

Baltimore’s big bopper Chris Davis is off on a race of his own. With 37 homers before the break, tying Reggie Jackson (1969) for best ever in the AL, talk of the single-season home run record is bubbling again.

But Davis doesn’t have his sights set on Barry Bonds’ 73 homers; he wants to top Roger Maris’ 61, the number he thinks is a legitimate, untainted mark.

“After everything came out, I assumed 61 was the record,” Davis said. “I think it’s what a lot of fans would agree on.”

Davis, whose previous career high for homers was last year’s 33, needs 25 homers in 66 games to reach 62. Of course, most of the rest of baseball goes with Bonds’ number, including Davis’ teammate, Adam Jones.

“He still hit them over the fence,” Jones said.

A HALF FOR THE AGED

Move over whippersnappers, the old guard is back — maybe.

Mike Trout, Bryce Harper, Matt Harvey, Patrick Corbin and a record 39 first-time All-Stars grabbed the spotlight in the first half, but expect to see some seasoned stars in the next few weeks that could impact the pennant races.

The injury-ravaged Yankees have hung around in the potent AL East with a “Who’s on First?” lineup. Now they should get Derek Jeter back after a one-game false start and Alex Rodriguez’s return from offseason hip surgery is imminent.

The St. Louis Cardinals have surged to baseball’s best record in part behind the pitching of some pretty good rookies. Imagine how much better they’ll be if the 2005 NL Cy Young Award winner, Chris Carpenter, is fully recovered from a nerve injury and bad back.

Talking about back, how about Manny Ramirez, all the way from Taiwan? The twice suspended slugger is hitting .300 with three homers in eight games for Texas’ top minor league club, Triple-A Round Rock, and the Rangers are in need of a big right-handed bat. Could it be Ramirez?

WHEELIN’ AND DEALIN’

After pushing their payroll over $200 million this offseason, don’t expect the Dodgers to sit quietly as the July 31 non-waiver trade deadline approaches. They got an early start, acquiring Ricky Nolasco from the Marlins to bolster the rotation and could make further moves.

The resurgent Red Sox might be on the lookout for another reliever after picking up left-hander Matt Thornton when lefty Andrew Miller was lost for the season with an injury.

Teams hoping to fill a spot in the rotation can call Cubs executive Theo Epstein. Matt Garza is up for grabs and he’s one of the most prominent names fans will hear in the next two weeks.

The flagging Phillies could look to move infielder Michael Young. The pitching-rich Giants might try to trade Tim Lincecum after he threw a no-hitter just before the break.

If A-Rod is unable to play because of his hip, expect the Yanks to seek a corner infielder. Pitchers Phil Hughes and Joba Chamberlain could be the bait.