Matt Riley arrived at the Baltimore Orioles' clubhouse this afternoon tired from a day of travel, still smarting from the pounding he received the night before and worn down from 180 innings of pitching this season, but ready for his major league debut on Thursday in Minnesota.

"All I asked for was the opportunity," he said. "You're never going to know if you're ready until you get the chance."

Riley, a 20-year-old left-hander who is penciled in to the Orioles' starting rotation next season, was called up from Class AA Bowie today. He is set to make perhaps the most important major league debut by an Orioles' pitching prospect since Mike Mussina in 1991.

"I'm aware" of the high expectations of the Orioles and their fans, Riley said. "I read stuff, I hear stuff. But as long as I pitch my game, I should be fine. You can feel [the pressure]. But you try to block it out."

In his final start for Bowie, at Akron on Saturday night, Riley gave up 10 hits and six earned runs in four innings in a 6-2 loss. But he finished with a 10-6 record and a 3.22 earned run average.

The decision to call up Riley had been much-debated within the organization amid concern about the toll of innings on his arm. But when Riley began showing signs of mastering a new change-up late in the season, the decision was made to bring him up this month, instead of giving him a month off and sending him to the Arizona Fall League.

"I'm worn down a little bit," Riley admitted. "It's been a long year, but it's going to be a learning experience for me."

Molina Is Recalled

The Orioles recalled reliever Gabe Molina from Class AAA Rochester after today's game. He will join the Orioles on Monday. Shortstop Jesse Garcia and first baseman Calvin Pickering also will be recalled and join the team Tuesday in Minnesota. . . .

Left-handed reliever Arthur Rhodes remains unavailable indefinitely with a bruised left index finger, which was injured by a line drive on Aug. 22. He pitched 2 1/3 scoreless innings on Aug. 27, but has not pitched since. "I guess I tried to come back too soon," Rhodes said. . . . Second baseman Delino DeShields is sidelined with a sore right hamstring. Jerry Hairston, who was called up from Rochester on Friday night, has been filling in.