WINGS MILLS, Md. — Kyle Boller was placed on injured reserve today by the Baltimore Ravens, ending his season and raising the question of whether the quarterback will throw another pass for the team.

Boller has been sidelined since hurting his shoulder in Baltimore's second preseason game against the Minnesota Vikings on Aug. 16.

"He has got either one of two injuries, either the torn labrum or he's got, I don't know the medical term, but there's a connection in the biceps to the shoulder that might be a problem," Ravens coach John Harbaugh said. "The torn labrum has not responded to the medication, and the other injury is a season ender. He's done."

Boller, selected with the 19th pick in the 2003 draft, was preparing for his sixth NFL season, all with Baltimore. He is in the final year of his contract, and it is uncertain if the Ravens will want to bring him back. Although Boller has started 42 games, his inconsistent play thrust him into a competition this summer with Troy Smith and rookie Joe Flacco to determine the starting quarterback.

Flacco won the job because of Boller's injury and Smith's lengthy battle with infected tonsils. Flacco will start Sunday against the Cincinnati Bengals, and his backup with be journeyman Todd Bouman, who was signed this week because Smith is not ready to return.

Boller was not available for comment. Since being drafted out of California, the 27-year-old completed 60 percent of his passes for a franchise-record 7,846 yards. But he has 45 touchdowns compared to 44 interceptions, and his uneven play was a factor in the Ravens' selection of Flacco as the 18th overall pick in this year's draft.

Still, Boller's teammates appreciate his love of the game and his effort to become a better quarterback.

"I've always said Kyle is my guy and I like him," receiver Derrick Mason said. "Regardless of what everybody else says, I think the guy can play football. To see him on IR now, and the hopes he had for playing this year, it's sad to see."

Tight end Todd Heap said, "He's obviously got to get his shoulder healthy. That's the first thing. It's unfortunate it had to happen this early in the season. He never got a chance to really get out and get on the field and do what he can do."

Heap, who has had his share of injuries, added, "That's football. Everybody goes through this. He's going to have to battle back from this one, get into the rehab and get healthy."

The injury means the Ravens must depend on Flacco, who was forced to start the final two preseason games because Smith and Boller were unavailable.

"Our mantra is next man up. If one guy goes down, we pride ourselves on being prepared. The second-tier players have to be prepared to play, and Joe is prepared to play," Mason said. "We've seen what Joe is able to do. On short notice, he had to play in the last preseason game and did very, very well."

After two preseason games, Flacco was virtually eliminated from the quarterback competition. But much has changed since.

"I'm a lot more prepared now than I was then," Flacco said, referring to his progress since the preseason opener. "I've had a lot more experience and worked with the guys a lot more. It will be a lot of fun. We can't wait to get out there Sunday and show what our offense is all about."

When it became apparent Boller and Smith would not be available Sunday, the Ravens worked out quarterbacks Chris Simms, Joey Harrington and Bouman. Bouman, who has thrown 230 passes during an NFL career that began in 1997, won the job.

"The other guys had very good workouts, but we thought he was the best fit for us," Harbaugh said.

The 36-year-old Bouman most recently played for Jacksonville. He began his career in Minnesota, where he served as the backup to Daunte Culpepper, and also played for New Orleans and Green Bay.

"I've been through this before. You just accept your role whatever it might be, whatever they ask me to do" he said. "You're one play away and have to prepare like you're going to be the starter. You've got to be ready. If you're not, then you're foolish."