Aaron Eccleston, who turned out for Old Hill Wanderers against Swinburne University reserves, was handed a second yellow card for the offence in the first half of last Sunday's match.
"During the first half, our player was struck in the groin by the ball, and left the field to receive attention," said a statement on the club website.
"At this point the referee became aware that he had a body piercing.
"He subsequently received two yellow cards, firstly for re-entering the field of play without the referee's permission, and secondly for privacy reasons being unable to prove that he had removed the piercing."
The latter end of the incident was captured on amateur video and posted on the Internet.
Eccleston, who describes himself on his Twitter page as a "disillusioned Mansfield Town fan, down under," was shocked at how quickly the story had spread.
"I don't think my mum's going to be particularly happy!" he tweeted.
The club accepted the yellow cards had been issued "in accordance with the laws of football" and apologised to the referee for the "negative attention that may have been generated by this unfortunate event".
The laws of football forbid players from wearing "anything that is dangerous to himself or another player [including any kind of jewellery]."
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