As leaders, we try not to spend too much time thinking about how much time our employees are looking for jobs while they are at work. Yet, as employees, we all know the best time to look for a job is when we have a job and while we are working at it.

It is a delicate balance. The problem is, as leaders we are often worried about the wrong thing. An employee who takes a call at lunch or is working on his resume during break is more than likely not the employee we should care about losing. Instead, it is the happy, productive superstars — the passive job seekers — who we should worry about keeping.

Here are a few ways to tell whether your star players are about to move to another team — and how to keep them from leaving.

Leaving the office

Star players somehow find a way to shine in their current position and network and attend professional development activities. Consummate professionals, they are organized and find ways to continue learning and growing, raising the standard on the team without being asked.

The thing is, it is not just clear to co-workers and managers that this employee has it together — everyone else they interact with can see their strengths. And as we have read time and again, personality traits are often seen as more important than job skills.

Thus, the first tip in keeping your superstars is to make a note of who they are and understand the tangible and intangible aspects of their contributions.

Strong network

Second, those same personality traits are what also help superstar employees make meaningful connections. In addition to having a strong active network, these employees are also the ones vendors, brokers and other organization service providers see as valuable assets.

As noted in this SHRM article detailing how to target passive job seekers, building long-term relationships is a key component in successfully attracting employees away from a job they like. Make sure to acknowledge the value of the relationships that employee has created for the organization.

Virtual ego folder

Finally, encouraging superstars to build strong networks and continue their professional development is a key to keeping them in the organization. And while it may seem counterintuitive, it is critical to take the next step and draw a clear connection between the employee's knowledge and relationships and the success of the organization.

Work with them to track their accomplishments, recognitions and awards so they can appreciate not just how much the organization does for them, but also how important their contribution is to the organization's success. Fortune and the research associated with their "Best Companies to Work For" lists highlight these meaningful contributions as critical reasons good employees stay.

The bottom line is: Looking for a job at work is a delicate balance, but if no one is egregiously breaking any policies, wasting time or simply talking about it too much, we can all continue go about our day pretending. The key for managers and leaders, however, is to recognize the characteristics of a passive job seeker, note the signs they may be courted and be ready to reward, promote or say goodbye to superstar employees.