Ed Balls left an opponent with blood streaming from his face when the pair clashed in a charity football match between MPs and journalists.
The Morley and Outwood MP’s elbow connected with a reporter’s face in a tackle during the annual match, which is held at the start of the Labour party conference.
The Northern Echo’s Rob Merrick reportedly needed stitches but returned to the pitch as the journalists’ team won the game in Manchester 3-1.
Both players said the clash was accidental.
Shadow chancellor and Norwich City supporter Mr Balls has played in the annual match since the 1990s.
He said after the match: “I was about to score a brilliant goal in the top right hand corner.
“As I steadied myself to shoot Rob came piling in from behind attempting to nick the ball and came off worst.”
Mr Merrick said on Twitter: “Starting #Lab14 at Manchester Royal Infirmary....but worth it! @LobbyXI 3-1 victory. Injury a complete accident.”