sweeper (soccer); libero (soccer)
In soccer, a defensive player who operates behind the main defensive line, sweeping up loose balls and initiating attacks. The term 'libero' is also used in English soccer contexts.
from Italian
libero (volleyball)
In volleyball, a specialized defensive player who wears a different colored jersey and has restrictions on attacking and setting. The libero cannot serve, block, or attempt to block.
He leads the last line of defense as the team's sweeper.
The libero specializes in receiving in the back row.