Calling .Close on a StreamReader object

I have a VB.net function that opens a StreamReader. Before the function ends I want to call the "Close" method on the StreamReader object. Do I need to first check if the StreamReader object is non null before attempting to call the close method? The reason I ask is that we have some scanning software that looks for null reference, or dereference exceptions. That is why I am asking if I need to check for null prior to calling the close method. See the very last line of code below.

Ex:
Function ReadData()

Dim myStream As FileStream
Dim fInReader As SreamReader
myStream = New FileStream(.....) ' Details of opening not shown in detail here. Just to give you an idea of how I create the file stream

if(finReader Is Not Null)
finReader.Close()