Mike Zimmer threw a giant bucket of calm the heck down on any notion of Kyle Sloter and his 137.1 preseason passer rating unseating Sean Mannion as the primary backup to Vikings quarterback Kirk Cousins.

Asked if another statistically strong preseason has moved Sloter any closer to Mannion, the Vikings coach said, "I don't know. I don't know that you guys [media] know all the little details about what you see in how he goes and does the game.

"He's got to get a lot better in a lot of the other parts of being a quarterback. Making the right checks, getting people in the right formation, making sure the motion is there, not missing the time clock when it's 8 yards in front of you. There's a lot of things he has to get better at if he wants to be the backup quarterback."

Sloter, a third-year pro with nary an NFL regular-season snap to his credit, has completed 85% of his preseason passes (17 of 20) with two touchdowns and no interceptions. Mannion, who has played 10 games with 53 passes and one start in four years with the Rams, has completed 66.7% of his preseason passes (18 of 27) with two touchdowns, one interception and a 96.2 passer rating.

Joseph returns to team drills

Walking off the practice field Tuesday after going through team drills for the first time this summer, Linval Joseph finally opened up about his offseason road to recovery and how he's not only back to full strength, but "Way stronger than I was last year."

The Vikings starting nose tackle, who had offseason shoulder surgery, thanked the Vikings medical, strength and athletic training staffs for bringing him back, at age 30, from what he called the toughest season he's endured physically in what's now a 10-year NFL career.

"Last year, after Week 5, when Danielle [Hunter] hit me in my leg, I want to say that was the hardest season I ever had to play," Joseph said. "Just my whole leg, my whole arm [hurting], I fought through it. I did it for my guys and gave it everything I had.

"I think the [rehab] stuff I was doing off the field [to come back] was way harder than practice. So to be back out here actually is a relief."

Joseph said he isn't sure if he'll play in the third preseason game on Saturday. Either way, he said team practice reps are all he would need to get ready for the regular season.

"Preseason for me at this point is to sharpen up my tool," Joseph said. "Nothing really can get accomplished in preseason for me team-wise. But just for my individual working on stunts, my hand moves, just polishing things up from the rust off last year. I can get that in practice because each day you practice you can get better."

In other injury news, right offensive tackle Brian O'Neill returned for individual drills only. Running back Ameer Abdullah, who missed Sunday night's game, returned to full practice.

Those on the active roster who didn't practice Thursday were receivers Jeff Badet and Olabisi Johnson, offensive tackle Aviante Collins and defensive end Ade Aruna.

No timetable on special teams

As for a timetable on pulling the trigger on naming a kicker, punter and holder, Zimmer said that, well, there isn't one.

"I don't think we have a timeline right now," Zimmer said. "Let's just see where it goes and make sure we're right."

Three weeks before the regular season begins, the Vikings have two more preseason games to decide whether unproven Kaare Vedvik replaces kicker Dan Bailey or punter Matt Wile. Receiver Chad Beebe continues to work as the holder with Wile's status uncertain.

Thursday, Vedvik kicked field goals with Wile holding. Wile handled the punting duties.

Vedvik made his first five attempts from 33, 37, 41, 42 and 46 yards. He missed his last two attempts, going wide right from 50 yards and coming up short from 59 yards to end the situation segment of practice.

Tom Baker for Star Tribune
Video (01:17) After having a good showing against Seattle, Vikings running back Mike Boone knows he needs to perform well on special teams in order to earn a roster spot.

Be like Mike, guys

Praise for second-year player Mike Boone has spread from his full-throttle, dual-threat work at running back to his dogged efforts on special teams.

In fact, Zimmer used Boone as an example to follow for other young skill-position backups who are fighting to make the final 53-man roster.

"I was impressed with what [Boone] did [Sunday night] probably more so than what he did at running back," Zimmer said.

Boone played 49 snaps on offense, carrying the ball 21 times for 66 yards and catching one pass for 45 yards. He played six snaps on special teams as either a blocker or cover guy.

Zimmer said there's a chance Boone will be given an opportunity as a returner.

Unimpressed by backup receivers

Meanwhile, the young backup receivers aren't impressing Zimmer. At least not as consistently as he had hoped.

"They're hard to separate right now," he said. "When we talk about it in personnel meetings, it's, 'one guy has a good day and then he has a bad day.' The consistency of what they're trying to do is really hard to get a handle on. That's why I say these special teams, they need to get their rear ends going on that."

Role for Hercules

Undersized backup defensive tackle Hercules Mata'afa will have his duties more narrowly defined in Saturday's preseason game. He'll play only in nickel packages as an inside pass rusher.

"I want to see if he can just pass rush," Zimmer said. "I think that's what his role will be this year, if that is his role. So I got to find out if he can go in there and rush on third down."