How to beat a backstabber at work

(Fortune) -- Dear Annie: I am the head of what I thought was a pretty strong, cohesive team. But I just heard from one of the people who reports to me that another subordinate went to my boss and said she could do my job better than I can. I'm not sure if there's some kind of ax to grind between these two subordinates, but this troubles me, since the person who allegedly badmouthed me is my top performer. (I jumped through flaming hoops to get her an extra 2% bonus last year.)

Now I don't know what to do. Ignore it? Feel out my boss to see if he's taking the criticism seriously? Confront the employee who is supposed to have stabbed me in the back? Your advice, please. -Vexed and Perplexed

Dear V & P: Eeek. I ran your question by Rich Moran, one of the smartest people around when it comes to thorny political situations at work. A longtime consultant with Accenture (Charts), where his clients included Apple (Charts, Fortune 500), Hewlett-Packard (Charts, Fortune 500) and Sega, Moran is now a partner at Venrock (www.venrock.com), a Menlo Park venture-capital firm. He's written six books, most recently Nuts, Bolts & Jolts: Fundamental Business and Life Lessons You Must Know (Rooftop, $14.95).

"There are at least two issues here," he says. "One is that you were betrayed by someone you went to bat for, so your willingness to trust your subordinates is not going to be easily restored. The second issue is, what happens in your company when people use the 'back channel' of communications" - that is, the unofficial channel where gossip and innuendo can thrive. "Do people generally believe it? If what people are saying is untrue, how do you work around it?"

Ideally, your boss views the "back channel" with a skeptical eye and isn't taking your scheming subordinate too seriously. But to be on the safe side, Moran recommends taking any or all of these three steps:

1. If your performance review isn't due for a while, ask your boss to expedite it: "In a meeting that is specifically about your job performance, you should be able to tell where you stand and whether your boss is listening to the back channel."

2. If official annual or semi-annual evaluations aren't scheduled for any time soon, you can still always have review sessions with people on your team. "You should sit down with each of these team members individually and address how you want communications to work," he says. "Don't utter the words 'Do not talk to my boss behind my back,' but be clear about the communications protocols."

3. Call a team meeting and, without singling anyone out, let it be known that you want to create a culture of trust in your group "and that you won't tolerate behavior that is less than worthy of that standard," Moran suggests.

Whatever you do, don't ignore this and hope it will go away. There is more than just your reputation at stake here, since a team whose members can't trust each other is a team that is well on its way to total dysfunction - and that's not going to be good for anybody.

Did you ever learn a subordinate or co-worker was badmouthing you to the boss? Or has an employee tried to badmouth someone else on your team? What did you do about it? Post your thoughts on the Ask Annie blog.

Are you part of the virtual workforce? That is, do you work from home or from some other location (such as client offices and airplanes) at least three days a week? Or do you manage people who work remotely and are reachable only by phone or e-mail? If so, I'd like to know: What's the biggest difficulty you've encountered with working or managing at a distance? (And how have you solved it, if you have?) Please send comments to Anne_Fisher@fortunemail.com and include a phone number where you can be reached during business hours. Many thanks!