It was a lost night for the Boston Red Sox.

First, the Red Sox lost an eighth-inning lead to the host Baltimore Orioles. Then they lost the game, 6-3. Then Boston learned it lost designated hitter David Ortiz, who will be placed on the 15-day disabled list with a partially torn tendon in his left wrist.

Ortiz leads the Red Sox with 13 homers and 43 RBI.

"He's a big part of the team," Manny Ramirez said last night after homering in a third straight game. "We have to keep battling without David. Let's wait for him and pray that he'll get better soon."

Ortiz received an MRI in Boston yesterday.

"Surgery is very unlikely," manager Terry Francona said.

The move to place Ortiz on the disabled list will occur today, Francona said, and Boston will recall righthander Justin Masterson from Triple A Pawtucket to fill Ortiz' spot on the roster.

Adam Jones broke a tie with a three-run double in the eighth inning, and the Orioles avoided a four-game sweep.

Ramirez' 12th homer of the season, in the sixth inning, gave him 502 for his career, two behind Eddie Murray for 23rd place in baseball history. Ramirez was the designated hitter in place of Ortiz, and likely will continue that role instead of playing leftfield.

In other games:

* At Minneapolis, Delmon Young drove in three runs and had three doubles as the Twins beat the New York Yankees, 6-5. Joe Mauer hit his first homer of the season for the Twins.

* At Arlington, Texas, Casey Blake homered twice and matched a career high with seven RBI as the Cleveland Indians beat the Rangers, 13-9.

* At Seattle, Ervin Santana (8-2) allowed two runs on six hits in 7 2/3 innings as the Los Angeles Angels beat the Mariners, 4-2.

* At Oakland, Bobby Crosby's ninth-inning single drove in Kurt Suzuki and lifted the Athletics over the Detroit Tigers, 3-2.

Noteworthy

* White Sox general manager Ken Williams isn't amused by Ozzie Guillen's latest tirade.

On Sunday, after the White Sox lost to the Rays on a walk-off homer in the 10th inning, Guillen ripped into his team again and called for Williams to make roster changes before Chicago plays tonight at home against the Kansas City Royals.

"It's just not a good idea to throw your boss under the bus, especially when that boss has had your back as much as I have had his," Williams wrote in an e-mail to the Chicago Tribune.

* Detroit relievers Fernando Rodney (shoulder tendinitis) and Joel Zumaya (recovering from shoulder surgery) are set to begin injury rehabilitation assignments today as they work toward their return to the majors. *