Alex Rodriguez insisted he wasn’t bothered by George Steinbrenner’s public criticism.The Boss told Joe Torre he didn’t mean it. And by the way, the Yankees sent struggling ace Randy Johnson for an MRI exam to make sure he isn’t hurt. Just another day at the Bronx zoo.

Johnson’s health is the most important matter, and apparently he is physically sound. Tests on his left shoulder showed nothing abnormal, the team said.

“We just wanted to get that aside,” Torre said. “Now he can focus on mechanics.”

The 42-year-old Johnson is 5-3 with a 5.01 ERA. He gave up seven runs – two earned – and five hits in 3 2/3 innings Tuesday night in a 14-3 loss to Boston, the fourth time in five starts he’s struggled. He also walked five batters for the first time since July 21, 2002, with Arizona.

“It looked like I didn’t have a clue out there,” he said. “I’m throwing balls to the backstop and trying to overthrow,putting more pressure on myself. I can’t remember the last time I pitched a good ballgame,” he said.

But Johnson was pleased with the test results yesterday.

“More than anything, getting a positive result from the MRI gives me a peace of mind,” he said. “I’ll be working over the next few days, physically and mentally, to put my best foot forward in my next start.”

The Big Unit is scheduled to pitch again Sunday against Oakland.

“There’s no medical issue. It’s basically normal.What we’re trying to do is eliminate possibilities. Now that medical is eliminated, it’s down to playercoach,” general manager Brian Cashman said.

The issue for Rodriguez is player-owner. After a sloppy game Tuesday night, the two-time AL MVP was singled out in quotes attributed to Steinbrenner in the press yesterday. Rodriguez made two key errors against the rival Red Sox, and Steinbrenner voiced his displeasure as he left Yankee Stadium.

“I’m upset at a lot of them,” he was quoted as saying.”The third baseman!”

But Torre said Steinbrenner called him yesterday and told him his comments were misinterpreted. Torre said The Boss told him he never meant to “get on” any of his players.

“It wasn’t an apology. It was basically that he doesn’t feel that way. That’s the best I can give you,” Torre said.

A clarification, he was asked?

“A clarification,” Torre said.

Torre told Rodriguez about what appeared in the papers, and A-Rod ac knowledged he was surprised that Steinbrenner singled him out.

“It’s been my first time,” Rodriguez said. “We all know the history of that. It’s pretty common.”

Rodriguez said it didn’t bother him.

“He’s the boss. He can say whatever he’s inclined,” Rodriguez said. “He signs everybody’s checks, so he’s entitled to it.When you’re the boss you can do pretty much whatever you want. He just wants to win.”

Rodriguez, often hard on himself, obviously wasn’t happy with his play Tuesday night.

“It was ugly all-around,” Rodriguez said, adding that he’s not going to “jump off a bridge” just because of a bad game against Boston.

“We’ve been playing pretty well, so we’ve just got to keep things in perspective,” he said.

Torre also said Rodriguez appeared Okay. “Alex is not going to always own up to what bothers him, but he seemed fine,” he said.

In other news, the Yankees aren’t sure whether right fielder Gary Sheffield will be ready to come off the disabled list when he’s eligible on May 21.

“I just can’t say right now whether that would be realistic or not,” Cashman said.