Manchester United star Cristiano Ronaldo is at the centre of a police probe after an Everton fan claimed he was stamped on during a match.
Merseyside Police on Friday confirmed they are speaking to witnesses and studying CCTV to establish precisely what happened during Saturday's match at Goodison Park when Everton faced Manchester United.
Carl Lloyd, 34, told the Daily Post newspaper that the Portuguese winger sank his studs into his right arm.
The joiner alleged the incident happened during the Premier League clash as he leaned over the advertising hoardings to retrieve the ball when it went out of play.
Mr Lloyd, of Wallasey, Merseyside, said he needed hospital treatment and said: "I've been in excruciating pain. I don't know if I'll work again any time soon. I couldn't believe what happened.
"All I was doing was trying to retrieve the ball."
A spokesman for Merseyside Police confirmed Mr Lloyd had made an official complaint and the investigation is ongoing.