Generally, see no way this is discriminating, but remote danger is if you do it this time for one employee and later in same circumstances don't do it for another employee that might have a protected characteristic such as race gender, etc.
This answer does not establish an attorney client relationship, nor does it constitute specific legal advice.
Discrimination generally involves treating an employee differently based on a protected category such as age, race, sex, national origin, disability, military service, and a few others. It sounds like your decision to place this employee on leave is based purely on a change in your business needs, which typically should not pose a problem. Of course, you can only provide so many details in a forum like this one. If you want to explore this issue in detail, contact a local employment attorney about your concerns. Good luck.