Many foreclosure experts advise against this, and say you are only asking for trouble.
Others swear by it, and say the former owner will make the best tenant, will take the best care of the property, and will probably stay the longest.
You just have to evaluate your property, your former owner, and your tolerance for risk. Any tenant is a potential problem.
If you are not comfortable with that thought, you should flip your foreclosure purchase rather than think about renting it out.