Eric Reid SF 49ers 2013 Training CampGary Radnich calls it “the biggest rip-off in sports.” The 49ers’ preseason schedule opens up with the Denver Broncos tomorrow, and from a season ticket owner’s point of view, it’s hard to argue Uncle Raddy’s stance. Paying full price for exhibition games featuring only cameos from the starters is an absolute racket. But for those of us who aren’t shelling out the money to watch live and in person, there are more than a few reasons to pay attention Thursday night.

At least the top reason on this year’s list isn’t quarterback. How many times did we go into exhibition games saying, “I can’t wait to see how the guy behind Alex Smith will play”? Or even worse, “I wonder how Alex Smith will look?” Nope, the 49ers got this starting quarterback thing figured out at long last. With that out of the way, let’s go over some positions to watch tomorrow night.

B.J. Daniels 49ers MinicampBackup Quarterback (and every other position B.J. Daniels can play)

Colt McCoy has been penciled in as the second man under center, but I’m more interested in seeing if B.J. Daniels can unseat Scott Tolzien as the third quarterback. Beyond throwing passes, Daniels has been a multipurpose weapon for the 49ers, playing running back, wideout and returning kicks. He’s someone to sit up and focus on during tomorrow’s game.

Free Safety

Vic Fangio announced that Craig Dahl will be starting at free safety for the exhibition opener, but let’s be honest: barring injury, Dahl won’t see the field on too many non-special teams sequences. Dahl will get reps with the first team and probably carry over action into the backups, while the man who will get an extended look is Eric Reid. BASG noted Reid looks ready to hit someone in practice, but my concern is whether he’s ready to cover someone.

The 49ers moved up into the middle of the first round to get Reid, a player Jim Harbaugh has coveted since recruiting him out of high school. They cut ties with Dashon Goldson, likely with a rookie free safety’s readiness in mind. Luckily, most rookie free safeties are ready. Tomorrow we’ll get our first look at Trent Baalke’s gamble.

Running BackLaMichael James 49ers

As much as I miss watching Frank Gore run (click here if you miss watching him run, too), even one carry would be too much at this point. The 49ers know what they have in Gore, and he’s better off on the sidelines of Bill Walsh Field in August. This gives us a chance to look at some of the other tailback talent on the roster.

We should get a considerable look at LaMichael James, although it’s probably safe to assume not at his very best. I have a hunch James will be used in a variety of ways we haven’t seen yet and if you’re expecting to see anything new from Greg Roman’s offense you’ll be sorely disappointed. That said, it’ll still be fun to watch the prolific Oregon back run in his second year.

Once James’s day is finished, we’ll get a shot to see some 49ers runners for the first time. The guys to keep an eye on are Jewel Hampton, who spent last year on the physically unable to perform list, and D.J. Harper, a talented rookie out of Boise State. Sorry guys, no Marcus Lattimore yet. Patience is a virtue.

Defensive Line/Pass RushersWill Tukuafu Lawrence Okoye

The 49ers have some interesting changes going on in the defensive trenches:

Nose tackleIan Williams has taken the role of starting nose tackle and he’s turning heads in the process, but how will Glenn Dorsey look in his first action as a 49er?

Defensive tackle: While Justin Smith and Ray McDonald are listed as first-stringers, Demarcus Dobbs will get a start at defensive end Thursday. How the backups fare will be something to watch, especially since the 49ers let Ricky Jean-Francois walk. Keep an eye on Dobbs, Will Tukuafu, Tony Jerrod-Eddie and Lawrence Okoye (he’ll be hard to miss) for a peek at who could step in should McDonald or Smith go down.

Outside linebacker: Aldon Smith will get at least a few shots at Peyton Manning — something the Broncos should probably plan for because he’s been looking downright scary in practice. Once he’s done, we’ll get a shot to see how well Parys Haralson recovered from his triceps tear. Corey Lemonier, the 49ers’ third-round pick out of Auburn, should get an extended look too.

CornerbackNnamdi Asomugha SF 49ers training camp

Here’s where things get interesting. While free safety may have a predetermined starter, the corner position opposite Tarell Brown is very much up for grabs. Chris Culliver was a big loss, but the coaching staff has been talking up Tramaine Brock quite a bit. He will see considerable playing time along with Nnamdi Asomugha, Perrish Cox, Lowell Rose, Darryl Morris and Marcus Cooper. How will Carlos Rogers look after coming back to earth in 2012? This is a position group to be watched closely on Thursday night.

Wide receiverA.J. Jenkins OTAs 49ers

This group has been the talk of training camp, and now we’ll get a chance to see what some of the younger guys can do. Kyle Williams is listed as the starting wideout opposite Anquan Boldin, but how much playing time Williams will get is unknown. The battle for this position should keep 49ers fans interested late in the game, because almost every receiver left on the roster has stood out at one point or another over the last couple weeks and has a shot to take important reps during the regular season. This team needs some extended looks at the progress of A.J. Jenkins, Ricardo Lockette, Austin Collie, Marlon Moore and the others as they look to replace Michael Crabtree, Randy Moss and Ted Ginn (WRs 1/2/3 during the Super Bowl).