The 18-year old Irishman has impressed during his initial month spell with the Owls and the Yorkshire club are keen to keep the midfielder for another month.
O'Brien has captained the Wanderers reserve team this season and is very highly thought of by everyone at the Reebok Stadium, who feel that he can progress further in the game.
Meanwhile both Blessing Kaku and Florent Laville have returned to the Reebok following spells out on loan with Derby County and Coventry City respectively.