This is Maurice Edu, formerly of Rangers and Stoke but now the captain of Philadelphia Union, wearing a microphone in their recent MLS game against the New York Red Bulls.
It's an NFL, F1 and cricket staple and we've recently experienced the brilliance of a mic'd-up rugby league player (the notorious NRL sledger Willie Mason), but this is a real rarity in football.
http://youtu.be/Z-oQ3Kr2m_s
See also: The phrases that have completely different meanings in amateur soccer