Marcus Mariota the unquestioned starter; Chris Clemons misses start of training camp and more

The Tennessee Titans will open training camp on Friday, and if there was any doubt about rookie quarterback Marcus Mariota and where he stands with the team, forget about it. On Thursday, head coach Ken Whisenhunt made it clear that any competition at quarterback begins "after Marcus," according to Jim Wyatt of The Tennessean.

It was always obvious the Titans took Mariota with the No. 2 overall pick (and passed up multiple reported trade offers) to be the organization's franchise quarterback. But a lot of the time, teams still have the rookie go through a competition to "earn" the starting role. Often times the competition itself seems rather farcical, and the Titans are not bothering with it.

Mariota will take the practice field as the unquestioned starter and with a lot of weight on his shoulders on Friday. The Titans have invested a lot in him and the offense this offseason, and all eyes will be on how he performs in training camp.

In other Titans news, outside linebacker Brian Orakpo is ready to go for camp, though the Titans might bring him along slowly just to be safe, given his injury history, via Wyatt. The team is also excited about rookie receiver Dorial Green-Beckham and is supporting Justin Hunter, who was arrested this offseason and charged with felonious assault.

Below, we've got other news and notes from around the league on Thursday.

Clemons not at start of Jaguars camp

Jacksonville Jaguars defensive end Chris Clemons was the lone player absent from the start of the team's training camp on Thursday. It's unclear why exactly Clemons, who did not participate in any voluntary organized team activities, was absent, though head coach Gus Bradley called it a personal issue, according to Ryan O'Halloran of The Florida Times-Union.

There was some thought that Clemons was upset about his contract, and also about a potentially reduced role this season, at least earlier in the offseason. There's nothing to suggest that's why he missed the beginning of training camp, but his absence is significant. Bradley said Clemons has some "personal things that he's going through," and that the team has been "in really good communication with him."

Perriman tweaks knee; White, Conley are day-to-day

Baltimore Ravens rookie wide receiver Breshad Perriman opened training camp running with the starters, and looked good doing it. Baltimore used the No. 26 overall pick on Perriman and he's getting right into the thick of things. Unfortunately, Perriman went down with a knee injury after going to the ground for a pass, and he left practice. He went back to the locker room, and while there's no word on what the injury was exactly, head coach John Harbaugh said it isn't serious, and that he'll be back "as soon as the knee feels good."

Perriman wasn't the only rookie wide receiver to have injury news on Thursday, either. Chicago Bears first-round pick Kevin White is dealing with a shin injury, and on Thursday head coach John Fox said that White is "day to day," and that his injury is not long term, according to Brad Biggs of the Chicago Tribune. Kansas City Chiefs rookie receiver Chris Conley is dealing with a knee injury of his own, and is considered day to day as well, according to Terez A. Paylor of the Kansas City Star.

Big-name players getting healthy

While there's plenty of injury news to go around, there are also updates on plenty of big-name players being declared 100 percent and ready to go for training camp. Cincinnati Bengals tight end Tyler Eifert declared himself 100 percent for the first time since OTAs last year, according to Paul Dehner Jr. of The Cincinnati Enquirer. Eifert will be counted on big time this season and should be full-go in training camp.

Green Bay Packers wide receiver Jordy Nelson had hip surgery this offseason, and head coach Mike McCarthy said on Thursday that Nelson is fully recovered and "hasn't missed a beat," according to Rob Demovsky of ESPN. Nelson is one of the league's top receivers and Aaron Rodgers will need him healthy. You can also add Baltimore Ravens offensive linemen Jeremy Zuttah and Rick Wagner to the full-go list, according to Aaron Wilson of The Baltimore Sun, and also Dallas Cowboys tackle Doug Free, according to Todd Archer of ESPN.

Johnson, Coleman have to earn starting roles

The Cleveland Browns have a battle going on at the quarterback position between Josh McCown and Johnny Manziel, but another important battle is brewing at running back. Terrance West, Isaiah Crowell and rookie Duke Johnson are in on the battle, and on Thursday West took the first starting rep at running back, followed by Crowell, according to Mary Kay Cabot of the Cleveland Plain Dealer. Johnson probably has a higher ceiling than those guys, but he'll have to earn his playing time.

When the Atlanta Falcons open training camp on Friday, another rookie running back with a ton of potential will have to earn his way into time with the starters. The Falcons will pit Devonta Freeman and rookie Tevin Coleman against one another in a battle for the starting job, but on Friday Freeman will take the first reps with the starters, according to ESPN. Coleman, like Johnson, has a high ceiling and should be considered the future of the position, but he'll have to earn his place.