49ers vs. Broncos: Who has the most to gain and lose on Thursday?

The 49ers and Broncos open their preseason on Thursday, which means it is time to focus on the randomest of the random! We'll spend much of the next six months talking about Colin Kaepernick, Frank Gore, Justin Smith, Patrick Willis and all the other big names. For the next month, the hard core fans get their fill of the guys deeper down the roster. Someone will likely surprise us and make the roster, while others will go the way of the Kory Sheets and Thomas Clayton types.

As we head into the first preseason game, it's time to figure out who has the most to gain and most to lose. I don't know that jobs are necessarily locked down in Week 1 of the preseason, but a player can give himself a strong boost, or completely shoot himself in the foot. While practice is important, Vic Fangio made the best comparison. Practice is the quiz, while game action is the test.

In looking through the 49ers depth chart, we've discussed plenty of these bubble guys looking to earn a spot. Cam Johnson, Michael Wilhoite, Marcus Cooper and others have gotten some play thus far. But there will be plenty others. Really, anybody getting playing time in the second and third quarter of this first game is likely a bubble candidate.

A.J. Jenkins is an obvious choice, and people can certainly talk about him. However, I wanted to use this more on guys we haven't focused in on quite as much the last few weeks.

One guy we haven't discussed much is offensive tackle Kenny Wiggins. He is listed as the backup at right tackle, but he hasn't been discussed a whole lot in training camp reports. Daniel Kilgore is the primary backup on the inside of the line, while Adam Snyder has been getting most of the work as the first OL off the bench after Kilgore. Wiggins spent last season on the 49ers practice squad. The 49ers drafted Carter Bykowski, who will likely be competing with Wiggins and Snyder for a roster spot. Wiggins cannot claim a job on Thursday, but he needs to build some momentum if he wants to snag a job.

The defensive line features several players competing for some unknown number of roster spots. Demarcus Dobbs gets the start on Thursday, and a solid performance would go a long way to sewing up his roster spot. Beyond that, we will be watching Will Tukuafu, Tony Jerod-Eddie and Lawrence Okoye. While Okoye seems destined for the practice squad, Tukuafu and Jerod-Eddie could be competing for one spot, or maybe even competing with Dobbs for a single spot. If Tank Carradine and Quinton Dial remain on the NFI list, that potentially opens up a spot alongside Dobbs and Glenn Dorsey/Ian Williams (whomever does not win the starting nose tackle job).

Which players do you see having the most to gain and lose on Thursday? Let's move beyond some of the obvious and get into the nitty gritty.