Quarterback Robert Griffin III will be on the shelf and the outcome means next to nothing. But there are some subplots to provide bits of intrigue when the Washington Redskins open the preseason Thursday night in Tennessee.

Kirk Cousins will get another chance to demonstrate his reliability as Griffin’s understudy. The three key rookies in the Redskins’ secondary will make their exhibition-season debuts. And linebacker Brian Orakpo and tight end Fred Davis will get their first tastes of game action, albeit merely of the preseason variety, since their season-ending injuries last year.

“It’s just a good opportunity,” Cousins said. “When the lights come on, when the situation gets a little bigger than a practice field, who’s able to rise to the occasion and who maybe backs away? We’re gonna find out. As a quarterback, nobody has a bigger stage. So it’ll be a good challenge to go out there and make sure I can still operate and function at a high level in a game environment.”

The Redskins already know they can win with Cousins when it matters. He crafted key victories for the Redskins last season with Griffin hurt, beating the Baltimore Ravens in relief and winning in Cleveland in his first NFL start. This dress rehearsal is of far less importance.

But Cousins talks about the need, in his role as Griffin’s backup, to take advantage of every opportunity he gets because his chances are so limited. It’s another chance for him to reinforce the considerable confidence those in the organization have in him. It is also an opportunity for him to show how much progress he has made while working with the starting offense throughout offseason practices and in the early stages of training camp with Griffin coming back from knee surgery in January.

The Post Sports Live crew previews the Redskins first preseason game against the Tennessee Titans. (The Washington Post)

“There will still be jitters,” Cousins said. “There will still be some nerves. That’s just part of it when you line up in an NFL stadium and play a game. But having been there before, I think, helps. And having had all these practice reps helps. It’s just a matter of going out there, seeing it correctly and executing. You’ve got to go out there and do that.”

Coach Mike Shanahan has said he intends to withhold Griffin from the Redskins’ entire four-game preseason. Griffin will have some company Thursday in being reduced to spectator status. Cornerback DeAngelo Hall, who missed practice time last week due to a sprained ankle, said Tuesday he won’t play against the Titans. Left tackle Trent Williams, who has been practicing with a sprained left wrist, and safety Brandon Meriweather, who has had his practice-field snaps managed cautiously as he returns from last season’s knee injury, are also not expected to play Thursday, according to a person with knowledge of the situation.

Rookies David Amerson, Bacarri Rambo and Phillip Thomas should get heavy doses of playing time Thursday while the front-line players from both teams remain on the field in the early going. Amerson is pushing for a starting job at cornerback. Rambo has practiced with the first-team defense throughout training camp. Thomas has made strides recently after falling behind when he missed a week of offseason practices.

The Redskins will pay careful attention to how all three progress, given the need for help for a pass defense that ranked 30th in the league last season.

“I’m very comfortable,” Rambo said. “I’ve been going with the [starters] the whole training camp. I’ve been learning a lot, asking questions. I’m been taking a lot of knowledge in to help me slow the game down so I can go out there full speed and make plays and just hit a couple people.”

The Redskins plan to play their starters roughly 10 to 15 plays Thursday night. It will be another, although perhaps modest, step in the comebacks of Orakpo and Davis. Orakpo is returning from last season’s torn pectoral muscle. Davis is coming back from a ruptured Achilles’ tendon. Both have been practicing in training camp without any apparent setbacks and both said they’re eager for the game in Nashville.

“It’s definitely good to go out there,” Davis said. “Whatever plays I’m in there, I’ll give 100 percent and try to play good . . . just taking a couple hits and running full speed and catching the ball. I just want to get back to where I was at a couple years ago. I think that’s what’s important for me right now.”

The Post Sports Live crew tries to make sense of Mike Shanahan's comments about the "different game plan" for quarterback Robert Griffin III's recovery. (The Washington Post)

Once the starters exit, younger players will take over and have a chance to make bids for roster spots and playing time.

“It’s just another chance to go out, play against another team, develop, get better,” Cousins said. “What are we going to get out of it? I’m going to become a better quarterback. . . . Anybody who goes out there and plays is going to become a better player as a result of the experience, whether it goes good or bad or in between. It’s a chance to go on the road, start a game, go through that whole routine. No matter what happens, I’ll be better coming out of it.”