middle-reliever

US /ˌmɪd.əl rɪˈliː.vɚ/
UK /ˌmɪd.əl rɪˈliː.vɚ/
1.

thuốc giảm đau trung gian

in baseball, a pitcher (= a player who throws the ball) who comes on to play instead of another pitcher during the middle part of the game:

:
He is relishing his new role as a middle reliever.