user: Question: Which player from the United States plays Defence and was chosen before round 5?
Columns: ['Round', 'Player', 'Position', 'Nationality', 'College/junior/club team (league)']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'Ryan McDonagh', 'Defence', 'United States', 'Cretin-Derham Hall ( USHS-MN )']
SQL:

assistant: SELECT "Player" FROM "Table" WHERE "Position" = 'Defence' AND "Round" < 5.0 AND "Nationality" = 'United States';