Motivated and engaged employees are what you hope for — they work at full speed, are up for any challenge or extra task and have a generally happy demeanor in the workplace. However, over time, employees might slowly start to act differently. Perhaps they aren’t putting in the full 110% or they’re constantly late to work or to meetings. It could even be as simple as neglecting the clothes they wear, when they didn’t before. These all may be signs of disengagement.

Disengagement is a slippery slope. At best, an employee has a rough patch and gets back to normal. At worst, the employee so completely disengages that they leave. If you’re seeing the signs, how should HR respond? Who is the best person to speak with the employee and how?

Below, 11 members of Forbes Human Resources Council share the signs of disengagement that they look for and how they go about finding a solution.