CREATE TABLE table_name_98 (league_goals INTEGER, name VARCHAR, league_cup_apps VARCHAR, fa_cup_goals VARCHAR, position VARCHAR)
What is the League Goals when the FA Cup Goals are 0, position is mf, League Cup Apps of 0, and name is Ben Thornley?
SELECT AVG(league_goals) FROM table_name_98 WHERE fa_cup_goals = "0" AND position = "mf" AND league_cup_apps = "0" AND name = "ben thornley"