ALLEN PARK, Mich. -- In training camps, players have bumps and bruises all the time. They sit out practices here and there -- sometimes at the request of coaches -- to save their bodies for a long, grueling season where everybody is hurting by the end.

It isn’t common, though, to see events such as those that happened Thursday. On the last fully-open practice of training camp for the Detroit Lions, 14 players sat out -- including five of the team’s eight tight ends. It’s a massive number -- 15 percent of the team’s roster -- that sat on the sideline.

The tally hit almost every position group: one running back (Matt Asiata), two wide receivers (Noel Thomas, Dontez Ford), five tight ends (Eric Ebron, Cole Wick, Tim Wright, Khari Lee and Michael Roberts), three offensive linemen (T.J. Lang, Cornelius Lucas, Laken Tomlinson), two defensive linemen (Bruce Gaston, Haloti Ngata) and one linebacker (Thurston Armbrister).

Some of those -- Ngata and Lang, for instance -- likely are cases of Caldwell measuring the reps of veterans, and they’ve sat out workouts before. Ebron has been out -- save for part of one practice in Indianapolis -- since getting injured the first day of training camp.

But it’s still something Detroit has to monitor. This is on top of four players still on PUP or NFI lists (Ezekiel Ansah, Taylor Decker, Sam Martin and Corey Robinson) and four players on injured reserve (Kerry Hyder, Mike James, Brandon Chubb and Des Lawrence). Another, linebacker Brandon Copeland, was waived and is expected to revert to injured reserve if he clears waivers Thursday.

Despite all of that, the Lions are not going to use players less just because of a bunch of injuries.

“You can’t play this game that way. You can’t coach it that way. You can’t play it that way,” Caldwell said. “If that’s all you think about is injuries, these are not pheasants under glass. They got to get out and they got to play and play the game.

“You don’t back down from that. If you get nervous and you're scared, you might want to go get another job. Do something else.”

That said, don’t be surprised if the starters play limited time Saturday against the Jets -- as usual for most teams during the second preseason game. Matthew Stafford and the Lions starters should see their most action next Friday against New England.

Other notes:

1. Back to the second team for Golladay: After one day where Kenny Golladay worked primarily with Detroit’s first-team offense, he reverted to mostly second-team duties Thursday with T.J. Jones regaining his spot with the starters. It’s likely to be a competition there -- one that could be based on field position and game strategy -- who is used when between Jones and Golladay early on. The difference is Golladay is a roster lock while Jones still has some work to do to earn the No. 4 receiver role -- although that seems to be more likely as the weeks go on. Don’t be surprised, though, if Golladay ends up running with the first-team offense more often as the season goes along.

2. Last-minute work: The tenor of practice was somewhat familiar Thursday for anyone who saw the Lions win last-minute game after last-minute game last season. Detroit spent part of its team period working on needing to score a touchdown driving down the field with :46 seconds left on the clock. Matthew Stafford and the first-team offense scored -- in large part due to a big pass from Stafford to Marvin Jones in tight coverage to set up a score. It didn’t go quite as well for Jake Rudock, who worked down the field with completions to Robert Tonyan before his pass into the end zone on the final play was incomplete to Keshawn Martin with good defense from D.J. Hayden. These types of drills are what Lions players continuously referenced last season when explaining why they were good late in games.

3. A'Shawn Robinson could be in line for a good season: There was evidence of this during the preseason opener against Indianapolis, when he had two passes defended. On Thursday, Robinson had another strong practice, blowing by Greg Robinson in an offensive line/defensive line one-on-one drill and generally being in Detroit’s offensive backfield a bunch. Considering the Lions’ major questions at defensive end and with a pass-rush in general, a lot will be needed of Robinson to become a playmaker in the middle. There’s a chance he ends up becoming that.

4. Some general thoughts after open practices are done: The Lions have a decent roster. Cornerback, safety and receiver are pretty deep and tough cut decisions are likely to be made there. Defensive end is a major question as the Lions -- unless they make a move for someone -- could end up relying on some unknowns to become contributors. Offensive line is still a mystery, although the starting group of Greg Robinson, Graham Glasgow, Travis Swanson, T.J. Lang and Rick Wagner appears to be set. Lang’s injuries are going to be something to watch, though. Jake Rudock looks well ahead of Brad Kaaya at quarterback -- that’s to be expected -- and there’s a large jump between Rudock and Matthew Stafford as well. But Rudock had a good camp, and appears to be the type of player who could take over if the Lions needed him to should something happen to Stafford. And that’s one of the things you want out of your backup quarterback.