The linemen and linebackers , close to the line of scrimmage , are often referred to as playing '' in the box '' , players outside '' the box '' ( usually cornerbacks and safeties ) are collectively referred to as the '' secondary '' .
The linemen and linebackers close to the line of scrimmage , are often referred to as playing '' in the box '' . 
 Players outside '' the box '' ( usually cornerbacks and safeties ) are collectively referred to as the '' secondary '' .