Detroit Lions coach Dan Campbell concerned by lack of reps for injured playmakers D'Andre Swift and T.J. Hockenson

ALLEN PARK, Mich. -- Through training camp plus two preseason games, first-year Detroit Lions coach Dan Campbell has been given a small sample size of what the new-look squad looks like during competition.

However, running back D'Andre Swift (groin) and Pro Bowl tight end T.J. Hockenson (shoulder) haven't participated in any preseason action while managing injuries.

Their lack of activity, especially with the season less than three weeks away, is something Campbell is concerned about. The Lions will host the San Francisco 49ers on Sept. 12 to kick off the 2021 regular season.

"The ones that concern me a little bit are the ones who haven't got much practice, you know. Swift concerns me a little bit, just with getting his wind back and being able to take a load, how much can he, where he's at," Campbell said. "He'll be out here today too. He'll be more involved than he's been, but those are the ones, to be honest with you. But it's always a challenge, yes."

Swift has been limited throughout most of camp, with the training staff being attentive to his body as he's projected to take on a larger role in Year 2. The Lions are being conservative with Swift, despite him calling the injury "frustrating" when addressing the media Thursday.

"That just shows me that they understand what's going on, just taking the time off to make sure I'm right so I can be able to produce and be consistent when I'm out here," Swift said.

If he lives up to expectations, Swift could very well end Detroit's run of not having a 1,000-yard rusher since 2013 -- the longest drought in the NFL.

For Hockenson, he's coming off a Pro Bowl season but has been hampered by an injury to the AC joint in his shoulder that the team initially described as "minor."

Hockenson says he isn't worried about any preseason action, or injuries, because he's "competing every day like it's a game rep" in practice.

"I'll be out there Week 1, so I'm not worried about it," Hockenson said Monday.

Campbell isn't as concerned about Hockenson's preparation level for the season with limited reps in recent practices because he was more active in the beginning than Swift. The tight end's connection with new Lions quarterback Jared Goff will be pivotal to any sort of Lions success this year.

"Yeah, I mean it is a little tricky, and I do worry about it a little bit," Campbell said, "but, I will say this. Here's the good news -- Hockenson doesn't worry me as much because he really got a good almost two weeks of training camp. So, he has a good base under him, you know.

"I think he can get to where we need him to get to relatively quickly. Especially once he comes off of this AC and we get him back next week. He'll do a little bit today, you know, but we get him back next week and really load him up. And then they'll have that three days off and then we'll get ready for San Francisco. So, I think he'll be OK, you know."