Rays ace James Shields won’t face the Red Sox tonight.

The Providence Journal / Glenn Osmundson

BOSTON — The Tampa Bay Rays are in control of the American League Championship Series against the Red Sox.

The Rays hold a 3-1 advantage with an opportunity to clinch their first World Series berth with a victory in Game Five tonight at Fenway Park. They have dominated the last three games in every aspect and clearly have momentum in their favor.

The Rays have a stranglehold on the Red Sox. So why would Rays manager Joe Maddon loosen his grip a little bit and allow the defending world champions a chance to breathe again?

That’s exactly what he’s doing by switching his scheduled starter for Game Five. Originally, ace James Shields was slated to go against Boston tonight. Instead Scott Kazmir will be given the ball. It’s a bold move by Maddon — one that could come back to bite him.

Shields is a fierce competitor. He’s the type of pitcher who wants the ball in a situation like this. He wants nothing more than to clinch a World Series berth by beating the Red Sox at Fenway Park.

Maddon explained the move early yesterday afternoon: Kazmir has better numbers at Fenway Park, plus if he does get into trouble the Rays will be able to utilize their entire bullpen as Game Five is sandwiched between a pair of off days. This will also allow Shields to pitch at Tropicana Field in the event a Game Six is necessary.

“We talked about it before the series even began,” Maddon said.

Kazmir has a career 4-4 record at Fenway with a 3.02 ERA, while posting a 2-3 mark with a 4.29 ERA against the Red Sox at Tropicana Field. Shields is 0-3 with a 10.13 ERA at Fenway.

But it’s the postseason and come October statistics go out the window.

If Maddon feels Kazmir pitches better at Fenway Park than Shields does, that’s fine. How did that work out for the Sox and Jon Lester in Game Three on Monday at Fenway? The southpaw was 11-1 at home this season before the Rays beat up on him pretty good.

Kazmir said yesterday afternoon he doesn’t know why he has decent success at Fenway, other than the fact he really enjoys pitching in that atmosphere.

The Red Sox have been down before in recent years. In 2004 they erased a 0-3 deficit in the ALCS and eventually beat the Yankees in seven games. In 2007, Boston trailed the Indians 3-1 in the ALCS and fought back to win, again.

This season is different. The Rays are clearly the better team. They’re healthy and riding a wave of emotion that could end with a World Series title. Boston has been waiting for that single moment when it could trounce its opponent and mount another comeback.

Maddon has given the Red Sox an opening.

“They’re a different team than they were last year,” he said. “We’re a different team. Everything is different. The world has changed. … We’re not looking to give them any kind of crack [in the door]. We believe Kaz can pitch well [today]. We’re just trying to look at the big picture.”

Interestingly enough Maddon admitted yesterday that he doesn’t like to deviate from his game plan.

“I don’t like making last-minute adjustments,” he said. “This is not one of those. This is something that had been thought out and we feel is the right thing to do right now. That’s why we’re doing it.”

Some of the Red Sox players and personnel were a little stunned by the move.

“They must have a good reason for it,” said the Sox’ Sean Casey. “But you don’t mess with success sometimes. They’ve had success with the way they have set things up, but they must have a reason and it must be a pretty good one.

“[Shields] is their horse, too,” Casey said. “You would think you would want your horse out there and see what happens. We feel like we’ve hit Kazmir pretty well and we feel like we’re in do-or-die situation. Our backs are against the wall and we know we have to win every game. There’s no letting down. We have to beat Kazmir in Game Five and he’s still a great pitcher.”

In five starts against Boston in 2008, Kazmir is 0-2 with a 9.67 ERA, including his Game Two start of this series where the left-hander allowed five runs on six hits in 4 1/3 innings at Tropicana Field.

Maddon has taken that one-game-at-a-time philosophy and tossed it right out the driver’s window. By making this move, he’s already planning on continuing this series in St. Pete over the weekend. If that does happen, no matter how the Rays were able to dominate both Josh Beckett and Lester in Games Two and Three respectively, they won’t have the same luxury in Games Six and Seven.

Behind closed doors, the Red Sox must be shaking their heads, wondering why the Rays wouldn’t start their ace in the potential elimination game. Publicly, the Sox are saying it really doesn’t matter who pitches.

“Our job is to win regardless of who’s pitching,” said Red Sox manager Terry Francona. “If they win, it’s not good. They can do whatever they want. That’s their right.”

Red Sox slugger David Ortiz, who is 1-for-14 in this series, also said it really doesn’t matter.

“It’s not that big of a deal,” he said. “Right now Shields is pitching better than Kazmir. …We need to get ahead in the game and that might calm them down.”

That’s not the only thing Maddon did yesterday that seemed a bit odd.

His club is on the cusp of ing the World Series. So instead of having a BP session during yesterday’s off-day, the manager gave his players the entire day off to do whatever they wanted. Some said they were planning sightseeing trips with their families and just relaxing.

The Red Sox held an optional workout, but a good majority of the players participated.

Sure, Maddon understands his players better than anyone. It just seems that his decision to switch his starting pitchers, and give the club the day off yesterday, might turn out to be the wrong decisions.

“Our team is loose,” Kazmir said. “It’s kind of like we don’t even realize the situation that we’re in right now. We’re just out there having fun and just playing our game.”

jmcdonal@projo.com