Leyton Orient F.C. is an amateur club.
FA Cup . The competition is open to any eligible club down to Level 10 of the English football league system -- all 92 professional clubs in the Premier League ( Level 1 ) and the English Football League ( Levels 2 to 4 ) , and several hundred `` non-league '' teams in Steps 1 to 6 of the National League System ( Levels 5 to 10 ) . Leyton Orient F.C. . In 1978 , they reached the semi-finals of the FA Cup for the only time in their history , under the management of Jimmy Bloomfield .