The next 48 hours will be the most nervous ones of the season for the Baltimore Orioles, on top of their second extra-inning loss to the Texas Rangers in two nights.

Don Slaught's two-run home run with one out in the 11th decided tonight's game, 5-3, an inning after reliever Don Aase, easily the Orioles' most valuable player, removed himself. And there's the big worry.

Aase took himself out after feeling pain just above his right elbow, the elbow that was surgically reconstructed in 1982. That's the elbow that has held the Orioles together this season with a club-record 27 saves, and if Aase is sidelined any length of time, the Baltimore pennant hopes could be over.

"I've had some tenderness in the elbow," he said, "although it's not in the area I hurt in 1982. When I threw a fastball to Darrell Porter in the ninth inning, it just didn't feel right. Kenny Rowe, pitching coach asked me after the inning if it was okay. I told him I was fine, but he came back again, and I said he'd better get someone ready."

After getting the Orioles out of the ninth, Aase went out for the 10th and threw two warmup pitches before calling Manager Earl Weaver out of the dugout.

"If this had happened before the surgery, I might try to ignore it," he said, "but I just can't take any chances. I don't think it's anything serious. It just wasn't right on that one pitch."

The Orioles are off Thursday, but begin a four-game series at Toronto on Friday. Aase hopes to rest the elbow a couple of days, then see if the pain has cleared up.

"I hope it's just fatigue," Weaver said. Tonight's appearance was Aase's 45th, in the team's 101st game.

Slaught homered off Nate Snell (2-1), the Orioles' fourth pitcher of the game. After Aase, Weaver brought in left-hander Brad Havens, who got the first two outs of the 10th, both against left-handed hitters. Weaver then brought in right-hander Snell, who got out of the 10th, but in the 11th allowed Steve Buechele a one-out single, which brought up Slaught.

For the second straight night, the Boston Red Sox and New York Yankees both lost, so the Orioles missed a chance to claim second place, 3 1/2 games out of first. They remain 4 1/2 out, and five American League East teams are within 6 1/2 games of the first-place Red Sox.

The Orioles entered the seventh trailing, 3-0, thanks to a three-run home run by Texas rookie Pete Incaviglia. They'd had only two hits off Jose Guzman, but after a home run by Cal Ripken and a single by Jim Traber, Texas Manager Bobby Valentine went to his bullpen, which had all kinds of trouble.

The Orioles did tie the game, on RBI by John Shelby and Traber in the eighth, but they also left the bases loaded in the seventh, eighth and ninth innings.

They only left two on base in the 10th when they twice failed to get a sacrifice bunt down, but still had the bases loaded and one out -- so that Juan Beniquez could hit into a double play.

Orioles starter Mike Boddicker failed to get his 14th victory, although he was outstanding again, allowing the Rangers five hits in eight innings, striking out eight and walking three.

Opening the seventh, Boddicker struck out Toby Harrah and Oddibe McDowell, then lobbed a slow breaking ball that hit Scott Fletcher in the thigh (Weaver argued Fletcher didn't try to get out of the pitch's way).

Fletcher stole second, and Boddicker intentionally walked Pete O'Brien, preferring to pitch to Incaviglia, a right-handed hitter. He played the percentages, and not the numbers, because O'Brien entered the game hitting .182 (four for 22) off Boddicker.

Regardless of whether the thinking was right, the first pitch to Incaviglia was wrong, a big lollipop breaking ball that hung in front of the plate. Incaviglia knocked it over the center field wall, his 17th home run, but first since July 7 -- and the Rangers' first three-run homer in 33 games.

Those runs held up until the Texas bullpen got a chance. Starter Guzman had not won since July 4 and had allowed 10 earned runs in his last 15 1/3 innings. He was a lot better tonight, allowing four hits in 6 1/3 innings. He retired the first seven Orioles before Tom O'Malley singled in the third. He allowed Ripken a one-out single in the fourth, but retired eight more in a row before Ripken led off the seventh with his 16th home run.

He got Jim Dwyer on a fly, but when Traber singled, Valentine brought in left-hander Mitch Williams. In 1 1/3 innings, Williams hit three batters, walked three and the Orioles got to 3-3 in spite of themselves.