Professional Footballers' Association chief executive Gordon Taylor has described Luis Suarez's alleged bite on Branislav Ivanovic as a "real dilemma".
Liverpool striker Suarez appeared to bite Chelsea defender Ivanovic during Sunday's 2-2 draw between the sides at Anfield in the Premier League.
"It wasn't good to see," Taylor told Sky Sports News. "It's incredible. We're so disappointed.
"His reputation for controversy continues to increase. It's a real dilemma. It's a shame for a player who is a really good footballer."
The Football Association has confirmed that it will review the incident as early as Monday.