Astrodome Roof Just Collapses on Padre Staff : Baseball: San Diego even uses an outfielder on the mound in a 13-3 loss to the Houston Astros.

The Padres hurriedly dressed, packed their bags and tried to think of the bright side to Sunday afternoon’s game.

Deciding that there was none, left the Astrodome wondering how long this possibly can continue.

In a game that the Padres described to a man as utterly humiliating, they lost 13-3 to the Houston Astros, suffering their worst defeat since May 26, 1990.

The game became such a mockery that outfielder Darrin Jackson actually pitched for two innings. The last time he pitched? Try 1981, when he was a senior at Culver City High School.

The most embarrassing aspect of Jackson’s performance, though, was that he pitched just as well as anyone the Padres put on the mound.

Jackson, the first Padre non-pitcher to throw in a game since Luis Salazar on July 29, 1987, allowed three hits and two earned runs, walking two batters.

“It was ugly, wasn’t it?” Padre Manager Greg Riddoch said.

The reason for the somber mood of the Padre clubhouse was not the lopsided defeat, but the health of starter Ed Whitson.

Whitson, who lasted a season-low three innings, revealed after the game that he has a strained right elbow, perhaps tendinitis, which could cause him to be placed on the disabled list.

Whitson, who said the elbow had been aching the past few weeks, will be examined today by Dr. Jan Fronek at Scripps Clinic. Whitson believes he might have tendinitis, because it’s in the same spot and similar pain to teammate Greg Harris, on the disabled list for that past month.

“It feels like someone stuck a hot nail in my elbow,” said Whitson, who gave up six hits and four earned runs. “It hurts. But we have so many guys on the DL (disabled list), you couldn’t afford not for me to start. I just had to go out there, but I had no pop.

“I don’t know, right now all I’m doing is hurting myself and hurting the team.”

Although the Padres have been keeping the injury a secret for the past few weeks, Whitson was allowed to pitch a complete game in his last start, allowing 11 hits in the Padres’ 7-3 victory over Atlanta. It was the most hits yielded in a complete game by a National League pitcher this season.

“I’ve had the tenderness in my last three or four starts,” Whitson said, “but I’ve been able to get by. But today, I had no chance. It took me 20 to 25, and I never could get loose.”

If Whitson indeed does need to be placed on the disabled list, he would be the 10th player to be disabled, requiring yet another roster move. The likely person to promote, if needed, would be Jose Melendez, who’s 7-0.

This is a pitching staff that can not withstand any further injuries. Their 4.38 ERA is the second-worst in the National League, and they have allowed 45 home runs, the most in the major leagues.

“We can’t afford it,” Padre center fielder Bip Roberts said. “We’re already short of pitching. We’ve got everybody from triple-A up here already but Jose Melendez.

“How much more can you take?”

The Astros, who have scored fewer runs than any team in the major leagues, used the Padres for batting practice.

They took advantage of Whitson’s aching elbow in the first three innings, scoring four runs, including Luis Gonzalez’s homer in the third inning. Gonzalez nearly had another homer in the first inning, but it was reversed and ruled a double when the umpires realized that the ball had not cleared the yellow striping of the new configuration.

It was Wes Gardner’s turn next. He retired only one batter, allowing two hits and three runs while walking three before mercifully being removed. Considering his ERA has ballooned to 7.08, he could emerges as a candidate to be removed from the roster when right-handed reliever Larry Andersen is expected to return late this week.

Mike Maddux saved any further embarrassment by getting out of the jam, and was the only Padre pitcher to record a 1-2-3 inning. There still was a semblance of a game when he left after five innings, with the Padres trailing, 7-1.

But once Maddux left, the Padres unraveled. The Braves hammered the Padres for three hits and four earned runs in the sixth inning, and yes, for the third consecutive game, Steve Rosenberg gave up a three-run homer.

“He’s been able to keep the ball down when there’s no one on base,” said Joe McIlvaine, Padre general manager, “but when there’s men on base, the ball’s up. I don’t know why, he’s got good stuff.”

It could be Rosenberg who prevents the Padres from releasing or trading Gardner. He has options left, which would allow the Padres to send him to triple-A Las Vegas without having to pass him through waivers.

Apparently, that was all Riddoch could stomach. He could have left Rosenberg in the game, and watch him get pummeled. He could have turned to right-handed reliever John Costello or left-hander Rich Rodriguez. Because the Padres have seven more games without an off-day, Riddoch hated to deplete his bullpen.

“I didn’t want to waste anyone in an 11-2 game,” Riddoch said. “The game was already out of reach.”

Uh, Darrin, remember how you talked about wanting to pitch some day, well, guy, here’s your shot.

Jackson started warming up in the bullpen in the top of the seventh, then had to run to the dugout and pinch-hit, and then had to take that long walk to the mound and pitch in a game for the first time in 10 years.

“(Riddoch) came up to me eight, nine days ago, saw me playing catch in the bullpen, and they asked me if I could pitch in an emergency,” Jackson said. “I said, ‘Sure, why not?’ I’d do anything to stay up here.”

So before Jackson knew it, he found himself on the mound, in front of a crowd of 15,726, and it sure looked a whole lot further than 60 feet, 6 inches to home plate.

“It’s not as easy as it looks, believe me,” Jackson said. “I knew I could throw strikes, but once I was out there, it wasn’t easy. I’m just glad they were helping me out by swinging.”

Jackson certainly didn’t thrive in his debut, but he did survive. He escaped by allowing only two runs in the seventh, and didn’t even wince when Ken Caminiti hit an upper-deck shot that was foul. And in the eighth, he walked Mark Davidson in four pitches.

Said McIlvaine, who couldn’t recall the Mets ever needing to use a position player in a game: “But if there ever was a day to do it, it was today. It wasn’t a mockery, it was a staff saver.”

McIlvaine paused, brought up that the Padres went 6-4 on the trip, but then his thoughts reverted to Sunday.

“What do they say, ‘Bad day, man, bad day,’ “McIlvaine said. “That was a very forgettable game.”