The England Under-20 international is set to train with the Tractor Boys on Monday and could feature in their Under-21 fixture against Colchester that night.
"Reece is joining us on Monday for the rest of the season," McCarthy said, in quotes reported on the club's official website.
Brown is the younger brother of Sunderland defender Wes Brown and has previously been on loan at Bradford, Oldham, Doncaster and Coventry.
