Can Johnny Manziel REALLY make it back to the NFL??
HELL YEAH ... so says Kurt Warner, who tells TMZ Sports the QB should take advantage of his shot with the Canadian Football League, then make his way back to America for a 2nd chance.
Warner -- who spent 3 seasons with the Arena Football League before going to the Rams -- says there's nothing wrong with taking an alternative route ... as long as Johnny keeps playing and stays out of trouble.
Warner sends a message to Manziel ... "gotta just keep workin', keep playing -- good luck to ya."