As rugby misdemeanours go, it hardly ranks alongside illegal drug-taking or deliberately kicking opponents in the head. Or, come to that, having England players splashed all over the tabloids for drunken antics in a dwarf-throwing bar.

But on Thursday England's Rugby Football Union was forced to suspend two of its coaching staff after an investigation found they smuggled Jonny Wilkinson's favourite ball on to the pitch during a World Cup match with Romania so he could use it for place-kicks.

Rugby regulations state the ball used to score a try must be used for the subsequent conversion, where the ball is kicked between the posts for an extra two points. But during England's match in Dunedin the team felt one of the eight numbered match balls used during the game was superior to the others for kicking.

Dave Alred, England's kicking coach, and Paul Stridgeon, the conditioning coach, were duly banned from attending crucial group game against Scotland for attempting to switch balls twice without the referee's knowledge.

Under its disciplinary rules, Rugby World Cup officials have the power to expel a player or even a team if they are found guilty of misconduct. Officials said: "We accept the RFU's assurances that it will abide by both the laws and the spirit of the game going forward. However … any similar breaches in future will be dealt with severely."

England are deep into a World Cup and about to play the biggest game of head coach Martin Johnson's tenure. Victory over Scotland would put them through to the quarter-finals. But they have now twice made the headlines for the wrong reasons during the tournament.

Officials have already had to defend the conduct of captain Mike Tindall after colourful details of a squad outing to a nightclub in Queenstown emerged. The Sun alleged that Tindall, who recently married the Queen's granddaughter Zara Phillips, was seen flirting with "a gorgeous blonde" while enjoying a "dwarf-throwing contest" in the town's Altitude bar.

Tindall was a spectator at the "Mad Midget Weekender" along with a number of other squad members. Pictures posted on the bar's Facebook site showed several England players in extremely relaxed mood but a team official insisted the night out had the management's blessing.

On the ball-switching incident, Wilkinson insisted his "dignity and integrity" were intact. He has struggled with his kicking game in New Zealand with a success rate of 50%, way below the kind of form that made him the team's high-scoring talisman in previous tournaments.

Should Wilkinson start missing his kicks against Scotland, the absence of his long-time kicking guru Alred from the sidelines will also be seized upon as one of the possible explanations.

If it were to coincide with England bowing out of the World Cup – which would happen should they lose by eight points or more – Johnson would be doubly furious. His brief statement – "It's unfortunate that we have had to take this action" – did not sound like that of a man impressed by the way events have unfolded.

But if England even think about blaming Alred and Stridgeon for a substandard performance it would be a case of drowning men clutching at straws. William Hill has them as 7-1 on favourites to win the match. Scotland are 4-1 against.

The contrast in atmosphere between the Scottish and English camps in Auckland was considerable even before the bans were announced. The Scots were focused and determined but surprisingly relaxed and upbeat. England, based only a couple of blocks away, were edgier and, in one or two cases, visibly frustrated. At least one senior player admitted he is not sleeping well, although the creaking floorboards in the passage outside his room were held primarily to blame.

Luckily for England, there is not always a correlation between happy media conferences and the outcome of a game of rugby. A little bit of pre-match angst, as Johnson keeps saying, is often a good thing. If his players were strolling around like men who already assume they are in the quarter-finals, the management would be far more worried.

Should England win, it is safe to assume Ballgate will barely rate a mention. Go out, and it will be a central plank of evidence for the verdict that this World Cup campaign has been disastrously mismanaged.

A gentleman's game



England's 16th man

England take heart: the last time they were accused of bending the rules at a Rugby World Cup they went on to win the tournament. In 2003 – when the competition was held in Australia – they briefly fielded 16 players against Samoa, when Dan Luger came on as a replacement with no one leaving the field. Luger played no part in the match but England were fined £10,000 and Dave Reddin, the man responsible for organising substitutions, was banned for two matches.

Bloodgate

During a Heineken Cup match against Leinster in 2009, the Harlequins winger Tom Williams came off with what appeared to be a bleeding mouth. This allowed a player who had already left the field, the kicker Nick Evans, to return, with the score 6-5 to Leinster. But it later turned out that the injuries to Williams were faked and Quins had used blood capsules bought from a joke shop in Clapham, south-west London. Several club officials, including the team director, Dean Richards, received lengthy bans.

Rugby's most famous dive

In 1978 Wales were leading New Zealand's 12-10 and looked like they were heading for what would be only their fourth ever victory over the mighty All Blacks. But New Zealand won a penalty for a push in the line-out, and subsequently kicked the winning points. Twenty years later the All Blacks' lock forward Andy Haden admitted he had dived to win the penalty, although the referee insisted he had whistled for another offence.