Assuming availability, you should be fine. I don't recall seeing anything on aa.com that excludes NetSaaver fares from same-day standby.

Edited to add:

I stand corrected. Some, but not all, netsaavers do specifically forbid standby before 7 pm on Friday.

I just tried booking a couple (chosen randomly). The fare rules on the DFW-DEN netsaaver prohibited standby before 7 pm, the DFW-BUR netsaaver did not.