Hi Arv,
Agree with Kunjal. However, I'm not clear though if this person is a new hire or existing employee of your organization.
New recruits and an existing staff will require you to handle the matter differently. Of course the first thing you should find out is why?
I don't believe you would end up hiring the wrong person for the job unless you don't have a proper recruitment procedure in place (but then again there is always a slim chance that it will happen)
For a new recruit, it may be due to 'fitting in' difficulties, then you may have to look at and assess your orientation again. Perhaps he needs time to adjust to the new work environment or have difficulties doing things the way your organization wants it to be done, perhaps colleagues are not giving him the necessary assistance/guidance etc etc etc...
If its an existing employee, perhaps it is due to boredom, lack of recognition, poor morale, disgruntle with work/fellow colleague/with the boss etc etc etc...
What I'm trying to say is there are a lot of possibilities and you need to find out the "root cause" and deal with it. Otherwise, you will still have this problem.
My humble thoughts
Regards
Ricardo