Clearly, Liverpool Football Club will be entitled to discipline Suarez and so will the Football Association and here is a player with a problematic disciplinary record. Leaving such action aside, what does the criminal law say about what might appear to be an assault by one player on another? The principal modern case is R v Barnes  EWCA Crim 3246 - Lord Woolf CJ, Cresswell and Simon JJ.
The prosecution of Mr Barnes was
under under section 20 of the Offences against the Person Act 1861. It arose out of a serious leg injury sustained by the victim during the course of an amateur football match in December 2002. The prosecution contended that it was the result of a "crushing tackle, which was late, unnecessary, reckless and high up the legs". The appellant admitted the tackle but claimed that it was a fair, if hard, challenge, in the form of a sliding tackle in the course of play, and that any injury caused was accidental. It was not disputed that the victim's injury was the result of the tackle and that the injury to his right leg amounted to grievous bodily harm.
Obviously, in contact sports there is risk of injury. Participants are said to impliedly consent to that contact inherent in the usual course of a game but the question arises as to when form of contact is such that the intervention of the criminal law is appropriate. Lord Woolf set out the position at paras. 4 to 16 of the judgment. The following is a summary only:
1. The existence of disciplinary procedures has the effect that, in the majority of situations, there is no need for criminal proceedings and such proceedings are undesirable. A criminal prosecution should be reserved for those situations where the conduct is sufficiently grave to be properly categorised as criminal.
2. When criminal proceedings are justified, possible charges are: assault; assault occasioning actual bodily harm - section 47 of the 1861 Act; unlawfully wounding or inflicting grievous bodily harm - section 20 of the 1861 Act; or wounding or causing grievous bodily harm with intent - section 18 of the 1861 Act. If, unfortunately, death results from the assault, the charge could be one of manslaughter or even murder depending upon the defendant's intent.
3. When no bodily harm is caused, the consent of the victim to what happened is always a defence to a charge. Where at least bodily harm is caused, consent is generally irrelevant because it has been long established in law that, exceptional situations apart, a person cannot consent to having bodily harm inflicted upon him.
4. To this general rule, there are obvious exceptions such as patients consenting to surgery. Another exception is physical injury in the course of contact sports such as football or boxing.
5. The House of Lords considered the law in R v Brown  1 A.C. 212. Brown dealt with a very different factual context, namely sado-masochistic activities between consenting adults. However, their Lordships made it clear that the rule and the exceptions to the rule that a person cannot consent to his being caused actual harm, are based on public policy.
6. Another interesting case illustrating this public policy approach was R v Dica  Q.B. 1257 - consent to sexual intercourse with HIV positive man when woman knew of his condition - there would be a defence to a charge under section 20.
7. So far as contact sports are concerned, the recognition that public policy is the foundation of the defence should not detract from the value of recognising that public policy limits the defence to situations where there has been implicit consent to what occurred.
8. The fact that the participants in, for example, a football match, implicitly consent to take part in a game, assists in identifying the limits of the defence. If what occurs goes beyond what a player can reasonably be regarded as having accepted by taking part in the sport, this indicates that the conduct will not be covered by the defence. What is implicitly accepted in one sport will not necessarily be covered by the defence in another sport.
9. The court looked at Canadian authority - R v Cey (1989) 48 C.C.C. (3d) 480 - Saskatchewan Court of Appeal- and also considered the views of the Law Commission - "Consent and offences against the person: Law Commission Consultation Paper No. 134."
The court approved an approach adopted by the then Criminal Injuries Compensation Board - "in a sport in which bodily contact is a commonplace part of the game, the players consent to such contact even if, through unfortunate accident, injury, perhaps of a serious nature, may result. However, such players do not consent to being deliberately punched or kicked and such actions constitute an assault for which the Board would award compensation."
In general, the court accepted the Law Commission's view that:
"the present broad rules for sports and games appear to be :
(i) the intentional infliction of injury enjoys no immunity;
(ii) a decision as to whether the reckless infliction of injury is criminal is likely to be strongly influenced by whether the injury occurred during actual play, or in a moment of temper or over-excitement when play has ceased, or "off the ball";
11. Whether conduct reaches the required threshold to be criminal will therefore depend on all the circumstances. However, there will be cases that fall within a "grey area," and then the tribunal of fact will have to make its own determination as to which side of the line the case falls. The jury (or magistrates) would have to consider (among other questions) whether the contact was so obviously late and/or violent that it could not be regarded as an instinctive reaction, error or misjudgement in the heat of the game.
12. In the case of offences against the person contrary to Sections 18 and 20 of the 1861 Act, it is a requirement of the offence that the conduct itself should be unlawful.
To return to Luis Suarez. Biting is not part and parcel of playing football and is a deliberate act. Intentional infliction of injury enjoys no immunity. The biting might amount to common assault or, if there is injury (however slight), to an offence under section 47 of the 1861 Act. It is unlikely in this instance to amount to an offence under section 20 or 18 - (Grievous = really serious - bodily harm).
R v Barnes was a case involving a tackle (part and parcel of the game - an attempt to win the ball) and it was a game at an amateur level where standards of play might be expected to be less than in a top-level premiership game involving professional players.
It is reported that Ivanovic accepted an apology. The matter will probably be left to whatever action is taken by Liverpool FC and / or the FA. For a further view see Gibbs Barrister - Suarez biting the hand that feeds him.