By Tony Moss, NFL Editor -- (Sports Network) - An uncertain quarterback situation could get one step closer to a resolution on Thursday night, when the Baltimore Ravens host the Atlanta Falcons in the fourth and final preseason warm-up for both clubs.

The competition among Ravens signal-calling candidates Troy Smith, Kyle Boller, and rookie Joe Flacco has been a hot topic throughout camp, and took a bizarre turn just prior to the team's 24-10 loss at St. Louis last Thursday night.

Smith, who was viewed by many as the most likely opening day starter, was forced to sit out the game due to a virus. Boller, who went into the game No. 2 on the depth chart, was unavailable while nursing a shoulder injury. Both players remain questionable for the Atlanta game.

That left Flacco, the No. 18 overall pick from the University of Delaware who played the entire game against the Rams. Flacco was 18-of-37 for 152 yards with a touchdown in the loss, and another reasonably strong outing on Thursday could improve his chances at winning the No. 1 job dramatically.

Also of note for the Ravens on Thursday will be the expected first appearance of the preseason for left tackle Jared Gaither. The second-year-pro, who is tabbed to start on the left side following the retirement of Jonathan Ogden, has missed all of the preseason to date with a sprained ankle.

Safety Ed Reed (shoulder) and running back Willis McGahee (knee) are unlikely to play for Baltimore, and cornerback Chris McAlister (knee) is regarded as questionable.

The quarterback situation for Atlanta was solidified earlier this week when the other first-round signal-caller taken in the April Draft, Matt Ryan, was anointed the No. 1 QB by head coach Mike Smith.

The Boston College product and No. 3 overall pick has posted a strong preseason to date, completing 32-of-52 passes for 277 yards with two touchdowns and an interception.

Ryan will likely play only sparingly on Thursday, along with the rest of the Falcons' first-string, before yielding to backups Chris Redman, Joey Harrington, and D.J. Shockley.

Expected to see action for Atlanta is veteran tight end Marcus Pollard, who was signed earlier this week after being released by the New England Patriots.

Baltimore opens its season on Sept. 7 with a home date against the Cincinnati Bengals, while Atlanta will host Detroit on the same day.

The Ravens are 3-2 against the Falcons all-time during the preseason, but were 13-10 road losers in the last such matchup, prior to the 2007 campaign.