Every leader grapples with low performers from time to time. And most will encounter a high performer whose antics require swift action. But there's an awkward middle ground that the majority don't know how to address: steady employees who are suddenly in a performance rut. Addressing performance issues as quickly as possible is always essential.

Burnout can be one cause. A 2018 Gallup survey of 7,500 full-time workers found that 23 percent feel burnout all the time; 44 percent feel it sometimes. That means a full two-thirds of employees experience burnout, and that exhausted, stretched-too-thin feeling can easily result in declining performance.

The opposite can happen, too. Employees who outgrow their jobs can check out and stop performing at the level they once did. In 2017 Psychology Today research showed up to 90 percent of Americans encounter boredom at work, which means a lot of people aren't working to their full potential.

Finding out the cause of unexpectedly bad performance is the first step to take, of course, but what do you do after that?

Not every employee will respond to "We need to talk" the same way. Based on your individual employee's personality, you have a few options:

1. Show them how they're impacting the team.

Employees whose lacking work is directly hurting other teammates need to know. This is particularly helpful with employees who are invested in being liked by their teammates -- they'll respond quickly to feedback that shows how they're negatively impacting others. To do this right, bring a couple of concrete examples to the table so you can outline the cause-and-effect relationship between their work and the other person's. Ask the underperformer to work with you to create a checklist to prevent these problems in the future -- this ensures he takes ownership of his own performance.

2. Make them clean up their own mess.

One thing that helps some low performers avoid the burden they've created is having someone else fix their mistakes. If a previously strong performer has made a mess of things, she's perfectly capable of fixing it -- so let her. Tell her directly that because she created the problem, you'd like her to solve it. Ask for documentation showing that she's cleaned up each aspect, whether that's simply correcting data entry or updating compliance forms. Feeling the brunt of her mistake will help prevent further errors.

3. Ask for amends.

Do you have an employee who's, shall we say, prideful? I had a high performer once who had gotten, as my grandmother used to say, "too big for his britches" and clearly had decided he could coast on his past successes. But by not fully training the people who were taking over some of the tasks he'd "outgrown," mistakes kept cropping up. I knew the best way to get him to deeply feel the repercussions of his actions was to introduce some (deserved) shame into the equation. I asked him to apologize in person to the two people he'd misinformed and then redo the training. We never had a problem in that area again.

4. Challenge them to earn something better.

An entrepreneur I coached had a high performer who'd grown bored. She wasn't lazy or pompous, but she was tired of doing the same thing day in and day out, and her attitude seeped out (and all over the team). I recommended that he ask her to prove she deserved to take on something better -- he couldn't promote someone who was just doing an OK job in her current role. She turned around her performance and outlined the three new tasks she'd like to take on if she could prove that she was capable of devoting time and energy to them, making both of them happy.

5. Get them help.

If someone's in a rut, it may not be related to work. Depression, undiagnosed medical issues could be to blame. If, after talking to someone about low performance, you're aware that it's due to external factors, work to mitigate them. To fight distractions, have the person sit with another team member who has a different way of doing things to learn new methods. If it's related to mental health issues, connect the employee to your employee assistance program. Be flexible about time off for medical appointments if needed. Make a point to help your employee address the underlying factors -- if he doesn't, they'll just follow him to the next role after he's inevitably fired.

Figuring out the right approach to low performance is tricky. The circumstances surrounding the performance are important, but picking the approach that will result in better behavior from that specific employee is even more so. If you're doing this right, you've hired a diverse team of people -- the ways you hold them accountable may need to be just as diverse.