What happened: Dan Campbell said Harper's injury does not appear long term. Clark has missed multiple preseason practices.
Why it matters: The absences thin the defense as roster competition reaches the week of the preseason finale. Harper entered camp competing for a safety spot, while Clark was part of the linebacker rotation.
By the numbers: Harper played 12 games last season, recording 37 tackles, one interception and five pass breakups. Clark has made 25 starts across four NFL seasons.
What to watch: Watch for Harper's practice status after this week and a clearer timetable for Clark.