Lions’ Dan Campbell provides injury update on LB Damone Clark and safety Thomas Harper

Detroit opened the final stretch of training camp with a reminder that its depth chart is still being adjusted, after coach Dan Campbell shared injury updates on two defenders during Tuesday afternoon practice. Linebacker Damone Clark is out indefinitely, according to the update reported by Yahoo Sports, while safety Thomas Harper should not be sidelined for much longer.

Campbell’s comments land at a practical moment for the Lions, when teams typically use the final week to compress their evaluation window. The focus shifts toward the players who can handle more repetitions with fewer substitutes, and toward identifying which roles can be filled internally if a starter misses additional time. With Clark listed as out indefinitely, Detroit’s day-to-day planning for the linebacker group becomes a moving target until there is more clarity on his timeline.

Clark’s absence matters because linebacker is a position group that typically carries a heavy load in training camp reps. In addition to run fits and coverage responsibilities, the position group often functions as a connector between the defensive front and the secondary. If Clark cannot participate in practice for an extended period, Detroit likely has to lean more on other options to handle those responsibilities as the staff continues to sort out its best combinations.

Harper’s situation is less severe in the report. The safety, Thomas Harper, “shouldn’t be out much longer,” per Yahoo Sports’ account of Campbell’s update. That phrasing indicates the Lions expect him back on a shorter timetable than Clark, but it still leaves an immediate gap to manage in the final week. Safety reps in particular can swing late, because they are used to prepare for the timing and spacing of coverage assignments against different looks.

The Lions have not been operating in a vacuum this camp. The reported injury updates come after both players have “missed some time as of late,” which suggests Detroit has already been shuffling work in recent days. For coaches, the problem with late-camp injuries is not only who is absent, but how much the staff can maintain continuity. Even when a player returns, it can take time to rebuild rhythm after missing practice stretches.

For fans, the most important takeaway is that the final week of camp is approaching while Detroit’s defensive availability is still being refined. Clark’s indefinite status creates uncertainty at the linebacker level, while Harper’s “not much longer” outlook suggests Detroit may be able to stabilize its safety group sooner rather than later. Together, the updates point to a defense that could look different by the time the Lions move deeper into their preseason preparation.

What to watch next is confirmation of whether Harper returns shortly and whether Clark’s indefinite timeline becomes more specific. Teams often provide additional clarification once players progress through whatever internal medical milestones determine practice readiness. Until then, Detroit’s practices will likely continue to emphasize depth, communication, and the ability of next-man-up options to execute consistently in live and near-live settings.

Injury updates can also affect how coaches allocate reps for players competing for roles across the defensive back and linebacker areas. If one player is held out longer, it can accelerate development opportunities for those currently behind them on the depth chart. If the Lions regain Harper relatively soon, they may be able to tighten their defensive packages earlier than expected, which is especially relevant as the team prepares for the next phase of the preseason timeline.