Scott Tolzein SF 49ersLost amidst the San Francisco 49ers’ thrilling offseason, where the most spine-tingling free agent signing thus far as been a 38-year-old placekicker, is a roster hole that hasn’t received much attention. The 49ers have one starting quarterback who’s up for the Madden cover (even though he only has 10 career starts, which is kind of ridiculous but whatever), and another who has never played in an NFL game.

Colin Kaepernick is QB-1, and Scott Tolzien will probably be one of the three quarterbacks on the roster at the start of the year. They will need a third quarterback, and they have two options.

1. Sign a free agent quarterback to compete with Tolzien 

Who’s available? 

Kevin Kolb, Jason Campbell, Rex Grossman, Tyler Thigpen, Byron Leftwich, Brady Quinn, Vince Young, Matt Leinart, okay I think we’re done here

Who makes sense?

That almost seems like a trick question, even though I wrote it. There really wasn’t much at the start of free agency on the QB front, and now things are incredibly bleak. Considering that the going rate for backup quarterbacks who can breathe seems to be about $2M-$4M per season, there’s no way the 49ers (about $4M-$5M under the cap) can afford Kolb. Not that Kolb is someone they should go for anyway, since he can’t stay healthy and probably wants to sign with a team where he can compete for a starting job.

While Campbell looked terrible against the 49ers, that Bears offensive line was phenomenally bad. Chilo Rachal starting bad. There’s also a chance that Campbell never recovered from the collarbone injury he suffered in 2011 while starting for the Raiders, and he averaged just over five yards per attempt after Cutler got hurt.

I think I heard Matt Barrows on the radio saying that the 49ers are interested in Tyler Thigpen, but I’m not sure why they would be. The 49ers may already be done with free agency anyway, something we’ll explore in the next couple days.

2. Draft a quarterback to serve as QB-3

Who’s available?

Geno Smith (West Virgnia), Matt Barkley (USC), E.J. Manuel (FSU), Ryan Nassib (Syracuse), Mike Glennon (NC St.), Tyler Wilson (Arkansas), Tyler Bray (Tennessee), Matt Scott (Arizona), Zac Dysert (Miami of Ohio), Landry Jones (Oklahoma), Sean Renfree (Duke), Nathan Stanley (Southeastern Louisiana), Alex Carder (Western Michigan), Collin Klein (Kansas St.), Tino Sunseri (Pitt), Jordan Rodgers* (Vanderbilt), Jeff Tuel (Wazzu)

Who makes sense?

You can remove Smith from that list, as he’ll probably be taken in the first half of the first round. After that, Mel Kiper’s guess is as good as mine. So, let’s examine what Jim Harbaugh likes in a quarterback. While Kaepernick has a cannon, neither Smith nor Tolzien are known for arm strength. One could say that Harbaugh likes smart signal callers, but that kind of goes without saying. Harbaugh does seem to like a tall QB — Smith is 6-4, Kaepernick is 6-5, Tolzien is 6-3 and Andrew Luck is 6-4. He also doesn’t seem to be interested in slugs who play like statues in the pocket.

Harbaugh’s dream backup would probably be Manuel, who’s 6-4 and can run. But in a year without many good quarterbacks at the top there’s a good chance some NFL exec will talk himself into drafting Manuel higher than expected (second or third round). It’s tough to imagine the 49ers taking one of the top five quarterbacks off the board with Kaepernick under team control for two more seasons and unlikely to leave after 2014.

The 49ers obviously see some good qualities in Tolzien. They pounced when he became available, and he beat out Josh Johnson (who recently signed with the Cincinnati Bengals) before the 2012 season. The 49ers have also shown no interest in any of the half-decent free agent quarterbacks. Exactly how much they consider Tolzien a part of their future plans will be evident during the NFL Draft.

If you see the 49ers grab a guy in the seventh round (they have four picks in the draft’s last round) and sign an undrafted free agent to compete during minicamps, that’s a pretty clear signal that the 49ers believe Tolzien is ready to take over the team if Kaepernick has to miss time. If the 49ers surprise everyone and grab a guy like Manuel, Nassib or even Bray (who is 6-6 and has an arm but comes with some character-related question marks) in the first four rounds, Tolzien might be in for another year on the inactive list.

* I watched Rodgers in person once, when I covered a game between Butte College and College of San Mateo a few years ago. Jordan is smaller than his brother Aaron, but he was a pretty dynamic runner as a sophomore. 6-1 is probably too short for a Harbaugh quarterback, and some other team may hope that Jordan has some of his brother’s magical qualities hidden somewhere in that smallish body, but if he’s available in the 7th round…