But Boller will not need surgery at this time, general manager Ozzie Newsome said yesterday.
"Kyle Boller could play again this season," Newsome said. "That could change, but this is good news."
But there was still no news about whether Troy Smith could play tonight. Smith has a "50-50 chance," as one team official described it. If Smith is sidelined for a second straight game because of tonsil troubles, rookie Joe Flacco will start again.
The decision to start Smith "could go up to the game," coach John Harbaugh said. "It just depends on how fast he gets his strength back. You'd love to be able to predict it and say, 'Hey, we know what's going to happen,' but there's just no way to know. You'll see as we go. We want him to play, and he wants to play."
Because the Ravens could be down to one healthy quarterback again, they are expected to sign a lower-tier quarterback as an emergency option. A league source said Casey Bramlet, who was recently released by the San Diego Chargers, is likely to join the team today.
If the injury to Boller is more serious - or becomes season-ending - the Ravens would have to consider signing a more experienced quarterback.
It's a thin free-agent quarterback group: Daunte Culpepper, Kelly Holcomb, Tim Rattay, Aaron Brooks, Vinny Testaverde, Jamie Martin and Craig Nall.
Another alternative is waiting for Saturday's cutdown, when a quarterback such as the Tampa Bay Buccaneers' Chris Simms could become available.
If Smith is sidelined along with Boller tonight, Flacco has a prime opportunity to jump further into the quarterback race.
Harbaugh was impressed by Flacco's poise but wants to see him continue to progress.
"He can build on everything," Harbaugh said. "I think some specific things would be to be more accurate and to get the ball out quickly. Across the board, [he has to] just continue to improve."
Baltimore Sun columnist Mike Preston contributed to this article.
roster breakdown
This is The Baltimore Sun's projection of how the Ravens' roster is shaping up heading into the final preseason game:
OFFENSE
Pos. In Bubble Long shot
QB Boller, Smith, Flacco None None
RB McGahee, Rice Ross, Patrick Haynes
FB L.McClain, Neal None None
WR Mason, Clayton, Figurs-x, D. Williams, M. Smith Harper, Wheelwright, Willis Carter
TE Heap, Wilcox Jones, Bergen, Heinrich None
OL Gaither, Grubbs, Brown, Yanda, Terry, Chester, Cousins, Kracalik Slaughter, Hale Kraus, Clarke, Reitz
DEFENSE
Pos. In Bubble Long shot
DL Pryce, Ngata, Gregg, Bannan, Douglas Parker, Gordon L. Williams, Campbell
LB Lewis, Scott, Suggs, Johnson, Barnes, Ayanbadejo, Greisen, Gooden Stills, J. McClain McCune
CB McAlister, Rolle, Washington, Walker, Ivy, Martin Prude, Pittman Phillips
S Reed, Landry, Leonhard, Zbikowski, Nakamura None None
SPECIAL TEAMS
Pos. In Bubble Long shot
K Stover None Czech
P Koch None None
LS Katula None None
PR-KR Figurs-x None None
x-listed twice as a receiver and returner
Next: Ravens vs. Falcons, tonight, 7
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