It's an interesting decision because the third preseason game is when the first-stringers get their most substantial playing time. As a result, the naming of the starter for Saturday would seem to be a bellwether for who starts the season, either Kyle Boller or Troy Smith.
This much is clear, though. It will not be rookie first-round draft pick Joe Flacco.
When Flacco went in during the fourth quarter - playing behind a shaky offensive line - he was immediately besieged by Minnesota defenders, much as he was by Patriots backups the week before.
The scene was familiar. Flacco retreats. Looks, looks, looks. Gong! Time's up. Bad guys arrive. Football pops loose.
However, later with less than two minutes left in Saturday's game, Flacco found his rhythm and (with a little help from a Vikings penalty that nullified an interception) drove the Ravens to within 13 yards of having a chance to tie the game. His final pass overshot the end zone.
Afterward, Harbaugh seemed most impressed with Flacco's self-critique, such as hanging on to the ball too long and misreading how much time he had left at the end of the game.
"Those are all things he was telling me in the locker room just now," Harbaugh said, "That's the kind of guy he is, 'These are the five things I can do better,' and that's got to excite you as a coach."
The Ravens drafted Flacco, in part, because he is a cerebral guy.
They sent several quarterback draft prospects copies of their offense. Flacco did the best job of deciphering it.
So it shouldn't be a surprise that Flacco would be the kind of quarterback who might concentrate on understanding everything, hence those awkward moments when he seems to hang on to the ball a second too long.
"I want to see things as much as I can," Flacco said Saturday night. "I don't want to just go out there and ... throw it blindly right to the defensive guys. I'm trying to go back there and process the information.
"I want to see the guy before I hit him. If that means holding on to to the ball for an extra split second, that's something you go through. Obviously, over time, I'm going to speed up and get better and make those decisions faster."
In the last drive, Flacco demonstrated he could process and execute. And that, he said, is when it feels like football.
He reeled off the exhilarating things about the final drive that covered 71 yards in 13 snaps with 1:52 left and no timeouts: Getting the ball out of bounds, checking down to the running backs, spiking the ball to stop the clock.
When he threw his final pass through the back of the end zone as time expired, he mistakenly thought he'd have a second or two left for another play.
"It's all about getting to the point where you just play," Flacco said of the learning curve. "At some point, everyone reaches that and it's just - how fast do you get there. I'm trying to get there as fast as I can."