loose forward
US /ˌluːs ˈfɔːr.wərd/
UK /ˌluːs ˈfɔːr.wərd/

1.
a player in the scrum who is not in the front row, typically a flanker or number eight
:
•
The loose forward made a crucial tackle to stop the opposition's attack.
•
Both flankers and the number eight are considered loose forwards.