SANTA CLARA, Calif. -- The San Francisco 49ers open the preseason Friday night against the Kansas City Chiefs at Arrowhead Stadium. Kickoff is set for 6 p.m. PT.

As always, the first priority for any team is to come out of the game as healthy as possible. With that requisite disclaimer out of the way, here's three things to watch from a Niners perspective in the exhibition opener:

Barkley and Beathard battle

Coach Kyle Shanahan said this week that the starters will play for about a quarter. So Brian Hoyer will get some reps with the first group before handing the reins to Matt Barkley and then rookie C.J. Beathard. The most likely scenario will have Barkley play the second quarter and perhaps into the third with Beathard taking over the rest of the way after that.

While Hoyer has been entrenched as the starter from the beginning of camp, Shanahan has indicated there's a battle brewing between Barkley and Beathard for the backup job. To this point, neither has separated from the other and both have had their share of ups and downs through the first couple weeks of practice.

Beathard has seemingly built some momentum lately as he's improved from where he was when he arrived.

“He’s still working through it, still in the process of trying to get better each day," Shanahan said. "I think C.J. has done a good job since he’s been here. He’s attacked it as hard as he can. I thought he’s got a good grasp of the offense throughout OTAs. Some days are better than others, just like all guys."

No decisions will be made after one preseason game, but this is the first chance to compete against a different defense and start building a case for the No. 2 quarterback job.

Line dancing

The Niners are starting to get some clarity on the offensive line after releasing center Jeremy Zuttah on Wednesday. Zuttah's release was largely the result of the efforts of incumbent center Daniel Kilgore. Kilgore has locked down the starting job and Joe Staley and Trent Brown seem poised to maintain their spots at left and right tackle, respectively.

But with Joshua Garnett dealing with a knee injury that will keep him out for more than a month, the Niners still have some things to figure out at guard. Brandon Fusco has been a mainstay at right guard and Zane Beadles has been the primary option at left guard since Garnett's injury, but the Niners have not hesitated to try different combinations.

Some of those different mixtures include Tim Barnes at center with Kilgore moving to guard and Barnes working at guard. Beyond just figuring out the best combination for the line, the Niners also want to find players who can offer the most versatility.

"You want to see these guys’ versatility," Shanahan said. "It’s not always exactly who’s the best, it’s how to fill out the best 53-man roster. There’s not always an obvious right answer. There’s stuff that you’ve got to fight through and you’ve got to pair guys together and you’ve got to think about injuries a ton. That’s why there’s a lot of different stuff you’ve got to try.”

Safety first

The Niners have a number of undrafted rookies who have flashed ability in the first couple weeks of training camp. None of those rookies have stood out more than the safety duo of Chanceller James and Lorenzo Jerome.

James has worked mostly at strong safety with occasional reps at free and showed a willingness to play physical and make the occasional play on the ball. Jerome has been exactly what was expected, which is to say he's been around the ball a lot and come up with his share of interceptions and fumble recoveries. He's also been more of an impact hitter than expected and earned reps with the first-team defense while the Niners deal with injuries at free safety.

It's not out of the question that James and Jerome could make the 53-man roster, but it's more likely that there's room for only one of them. They've both showed they can play in practice but they still have some proving to do in game situations. Jerome, in particular, will be playing under the watchful eye of defensive coordinator Robert Saleh.

"He’s an instinctual football player," Saleh said. "Sometimes I look at the tape and I’m like, ‘I don’t know if you can do that bud.’ But, he always ends up in the same spot. He has a good feel, and again, he’s a rookie and he’s going through and he needs all the reps, and he needs to see it over and over again. He’s been doing all right.”

Also worth watching in this competition is if either player shows well on special teams. If James and/or Jerome are to make the roster, special-teams skills will have to play a part.