Michael Zagaris / Contributor

SANTA CLARA — “Hitting” is a loosely defined, somewhat double-edged term in NFL training camps. As Kyle Shanahan explained this past weekend, you promote physicality during these practices, but you don’t do so at the expense of a player’s health.

There had not been many legitimate hits resulting in players on the ground throughout the 49ers’ camp, but Thursday provided an exception.

During 11-on-11 drills, rookie linebacker Fred Warner leveled fullback Kyle Juszczyk on a pass over the middle. It was a bang-bang play, leaving both players with minimal time to react.

Juszczyk bore the brunt of the hit, hitting the ground and lying there for about three minutes. Practice stopped. Warner wore a blue penny throughout practice to signify he would not hit. He entered Thursday with a minor chest injury, and the 49ers didn’t want to push it. After the play, 49ers offensive players chirped at Warner for hitting while wearing the penny, with Warner raising his hands in the air, as if to claim innocence, before sauntering away from the pack.

Fortunately for the 49ers, Juszczyk eventually rose to his feet. It appeared he had the wind knocked out of him, and he was not diagnosed with an injury. Warner later approached the 49ers fullback and shook his hand to make amends.

“I know his intent and where his heart is at,” defensive coordinator Robert Saleh said post-practice. “That was an accident.”

The team split off into individual drills for the ensuing 10-to-15 minutes. Warner stood with the linebackers, hands on hips, looking onward, clearly showing the hit’s lingering effect in his mind.

“It’s one of those that happens so quick for him to bounce out of it, I guess,” Saleh said. “There’s a lot of plays in there where Fred actually did avoid contact where he was supposed to. But, that one was just so quick and so fast that it was almost like he was bracing for contact. It was completely accidental and thankfully [Juszczyk] Juice is alright.”

Warner has impressed through the opening seven days of practice largely because of that physical mindset. The rookie linebacker entered his first camp with a reputation as a cerebral, rangy linebacker. Scouting reports of him pointed to finesse before physicality.

But Saleh has lauded his violent attitude all camp long.

“That play withstanding, he has shown physicality,” Saleh said Thursday. “He has got the right mindset. So, he’s checking off all the concerns.”

Backup tight end injured

Backup tight end Cole Wick was carted off the practice field Thursday after suffering a knee injury. He was taken for further testing after practice. There have been no additional updates at this point.

On Monday, at a Levi’s Stadium event, John Lynch said Kyle Shanahan had recently texted him saying they needed to scoop a tight end because Cole Hikutini had suffered a groin injury. Hikutini did not practice again Thursday, though the injury is not considered serious.

The news of Wick’s injury exacerbates the issue, which could be short-term or long-term depending on the injury’s severity. Wick sits at fourth on the depth chart behind George Kittle, Garrett Celek, and Hikutini.

Garnett’s absence surprising Shanahan

Shanahan broke from the positive coach-speak that typically fills NFL press conferences, especially at this point of the season, after practice Wednesday. He was asked about right guard Joshua Garnett’s knee injury, which is considered day-to-day. The 49ers head coach was surprisingly forthright in response.

“I was a little surprised Garnett didn’t make it (Wednesday),” Shanahan said. “I’d be more surprised if he’s not out there (Thursday).”

Sure enough, Garnett did not practice Thursday.

Jonathan Cooper, whom the 49ers signed to a one-year deal this offseason, missed the opening five practices with a knee injury but returned to practice Tuesday. Shanahan has identified the right guard spot as one of the team’s open competitions, along with punter. Garnett, Cooper, and Mike Person will battle it out for the starting position.

Garnett’s absence, and Shanahan’s comments regarding it, have been surprising considering recent events.

The 49ers coaching staff placed Garnett on injured reserve prior to the 2017 season, challenging him to improve his physical condition entering Year No. 3. Garnett responded this offseason, losing about 20 pounds, better equipping him for Shanahan’s outside zone-heavy offense.

“I see a guy who’s really going for it,” Shanahan said in May. “I’ve been very proud of how he’s handled his year off.”

His tone has shifted in recent days.

Key players resting

The 49ers handed out rest days to several marquee veterans, including Joe Staley, Jerick McKinnon, Pierre Garçon, DeForest Buckner, Earl Mitchell, Richard Sherman, and Malcolm Smith. Jimmie Ward (hamstring) did not practice for the second straight day. He is considered day-to-day.

Shanahan, the “vicious” film-student

Saleh’s vocabulary is laced with classic, rugged football jargon. The 49ers defensive coordinator describes his ideal defense as “violent.” The mantra he has given his unit is, “all gas, no breaks.”

So, it should not be surprising that Saleh used a similar descriptor to characterize Shanahan’s film-study habits.

“He’s vicious when it comes to film work and all that, it’s awesome, because there’s no stone left unturned with him,” Saleh said.

Saleh explained that Shanahan has the same “tenacity” from a year ago, his first as a head coach, in the film room. Rookie receiver Dante Pettis reiterated those comments, though he sounded much more like a 22-year-old.

“I was just telling my friend earlier, I was like, ‘I don’t know how all these coaches know all this stuff that they know,’” Pettis said. “Like I don’t know how they see everything and they already know what’s going on, or what’s going to happen. I have been very impressed by the way (Shanahan) breaks down film.”

Odds and ends

-The 49ers offense struggled to move the ball throughout 11-on-11 drills Thursday. The lone bright spot, however, was Marquise Goodwin, whose blazing speed has dazzled throughout camp. He and Garoppolo connected on a 75-yard touchdown in which Goodwin blew by Ahkello Witherspoon, who never caught up. Goodwin later elevated and caught a 40-yard pass near the sideline. Garoppolo’s oft-critiqued long-ball was pinpoint Thursday.

-Adrian Colbert took an interception for a touchdown for the second time this week. On Thursday, Kendrick Bourne dropped a pass, and the ball hung in the air. Colbert snagged the interception and ran it back for about 30 yards.

-Drops were a common issue early during Thursday’s practice. Pettis, Bourne, Goodwin, and Richie James dropped catchable passes in either individual drills or run-throughs.

-Solomon Thomas and K’Waun Williams each broke into the backfield for would-be sacks, had hitting been allowed. Thomas fooled Garry Gilliam with an inside move, and Williams later went unblocked on a corner blitz.

Looking ahead

The 49ers will practice Friday before taking Saturday off. They will host the Dallas Cowboys in their first preseason game next Thursday night at Levi’s Stadium.