MLB

ALL-AROUND BAD JOBA FOR YANKS

ARLINGTON, Texas – Joba Chamberlain assumes he will enter the Carl Pavano Memorial MRI tube today at New York Presbyterian Hospital.

Has there been a more frightening sentence in the Yankees Universe this season?

On a night when the game-time temperature was in triple digits, the spines of Yankees fans everywhere went cold at the sight of Chamberlain walking off the mound with trainer Steve Donohue in the fifth inning last night at Rangers Ballpark.

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Initially, the club announced Chamberlain’s right shoulder was stiff. After the game, however, manager Joe Girardi and Chamberlain – the cornerstone of the Yankees’ pitching future – both said it was lower, more near the deltoid muscle in the front of the upper arm.

“[I’ll be going for an] MRI, I assume,” Chamberlain said after Marlon Byrd’s game-winning, two-out, bottom of the ninth grand slam off Damaso Marte carried the Rangers to a 9-5 win in front of 33,813. “They did some (resistance) tests and nothing is weak.”

After giving up a three-run homer to Michael Young in the fifth, Chamberlain fanned Josh Hamilton and was working to Byrd when he felt something “grab” in the arm. When he started shaking his arm, Girardi and Donohue went to the mound.

According to Girardi, Chamberlain will miss Saturday’s start against the Angels in Anaheim, Calif. With Dan Giese replacing Darrell Rasner for Friday night’s start and Rasner suffering from a blood blister on the right index finger, the Yankees will need to get creative to find Chamberlain’s replacement. That could mean promoting Alfredo Aceves or Ian Kennedy from Triple-A Scranton/Wilkes-Barre.

“It’s a little stiff, that’s why I am going back and get it straightened out,” said Chamberlain, who thanks to five straight quality starts and a filthy arsenal was on the cusp of being ordained as the Yankees’ No. 1 starter.

Now, he will have tests today after giving up five runs and eight hits (two homers) in 42/3 innings.

“Hopefully I will miss one (start) if that’s the case,” Chamberlain said.

With a healthy Chamberlain, the Yankees aren’t a lock to make it to October. Without him, baseball’s biggest month, one the Yankees are built for, likely will be dark in The Bronx.

“Life is too short to worry, the strength is good,” said Chamberlain, who spit the hook on a loss when Xavier Nady’s eighth-inning homer tied the score, 5-5. “You hope everything is okay.”

The Yanks were leading 3-0 thanks to Jason Giambi’s RBI single in the first and solo homers by Giambi and Robinson Cano in the fourth against Vincente Padilla and Chamberlain on the mound, and everything looked more than okay.

But David Murphy hit a two-run homer in the fourth and Young took Chamberlain out to right-center for a three-run homer and a 5-4 lead in the fifth.

“I made two bad pitches and they did what they are supposed to do,” Chamberlain said. “Michael Young makes his living to right-center.”

Nady’s fourth homer as a Yankee tied the score, but Marte’s wildness – he walked three in the ninth – led to Byrd’s homer to center field.

“I tried to throw my best pitch, a fastball a way,” Marte said. “I threw it too high.”

And Byrd hit it too far.

Because the Rays and Red Sox lost, the Yankees failed to gain ground in the AL East and the wild card chase, where they are 5½ games and 2½ games out.

However, that was overshadowed by the news that Chamberlain, a pitcher the Yankees have gone to great extremes to protect, was on his way to see Dr. Stuart Hershon and be stuffed into an MRI tube.

george.king@nypost.com

Rangers 9 Yankees 5