The full glare of England's football focus was on one England player's foot on Wednesday, as Wayne Rooney flew back to the UK for medical checks.
Police initially look for certain clothes, ages and flags
But at UK ports and airports, the football police had their eyes on a wider scene - potential troublemakers travelling to Germany.
If people fitted the profile - men, aged 15 to 45, casual clothes, England flags poking out of bags - their journey was halted by football
intelligence officers at Heathrow's Terminal 2.
Under Operation Jardon, they pull people aside and check their passports for previous violent disorder convictions which could prevent their departure.
It's one frontier in the campaign to stop England fans potentially being involved in violence at the World Cup.
By now, 95% of the 3,380 people with banning orders have surrendered passports for the period. Police are hunting the others.
If any are unwise enough to turn up at as obvious an exit as Heathrow two days before the tournament starts, they will be stopped.
Also sought are the peripherals who would likely step in to a fight to support the hardcore of violent offenders.
They might not have an order over their heads, but police say their history suggests they are a threat, past convictions or not.
PC Pete Dearden is a specialist officer who usually deals with football intelligence at Arsenal. What were "hooligans" are now called "risk supporters".
He is checking computer records and asking questions as people pass through the security scanners - who do they support? Where are they staying in Germany?
He knows by face and name the two Arsenal men still outstanding for not handing in their documents. But how do police spot the untold others who might want to cause trouble?
After years of building up an intelligence picture, there are key pointers they look for.
It is not rocket science, but then, they say, their quarry do not employ advanced tactics either.
"The types we are looking for are casually dressed, not in football clothes, but in certain types of clothing, Stone Island jackets, Burberry.
"They are aged 15, right the way up to 45. Quite relaxed," says PC Dearden.
"You'd be brave to go through police, immigration and press at Heathrow, but they do."
If stopped, people with a violent criminal history can be arrested and ordered to appear before magistrates within 24 hours.
If there is no cause for concern, they receive advice on how to steer clear of trouble in Germany.
Ben Eaton and friends Mike Stenbridge and Paul Lappas, all students, 21, stand out in their England tops and are pulled aside.
They show police their membership cards for the official England supporters' club and are advised they will come in handy if stopped by police in Germany.
Ben says checks are "a good idea if it stops people that have got convictions going to the World Cup. We don't want any trouble when we go out there."
Offences thrown up
With a shaved head, nondescript top, and England flag in his holdall, Danny Smith also fits the intelligence profile.
But, at 18, and with a mum at home worried about his trip, he represents the dilemma police face in who to stop.
His is allowed through, but his check brought up a previous minor offence he did not think would be on the system. That has unsettled him - he is just here to travel to the football.
Ben Eaton says it is important fans feel safe in Germany
"It's quite annoying in stopping us for no reason," he says. "If I hadn't had the England flag... I should have hidden it.
"I support police stopping people who are going to do something, but it's just me and a mate."
This part of the operation is high-profile. The police are keen to spotlight the two German police officers here, part of a six-strong team working in the UK this month.
It is hard to see in practice what Inspectors Sandra Kessing and Ronald Makowsky can achieve other than a visible presence. They have no powers of arrest.
It is their first day at Heathrow since arrival on 31 May. They have been seen at other airports - Manchester, Luton and Birmingham.
"Our role is to emphasise close co-operation between the British and German police. We are working alongside, patrolling with our colleagues," says Insp Kessing.
"We can give advice if there is a person that might be rejected in Germany."
No arrests have been made by the Metropolitan Police so far and no new banning orders handed down by magistrates, but one man has been banned from travelling after he was detained at Stansted.
Up to 50 officers are on duty at Heathrow while England remain in the competition. Regional forces have increased staff at all UK ports, and Eurostar terminals.
More than 80 UK police will be in Europe for the World Cup, also with no powers of arrest. Forty-eight will be in uniform. Some will be in countries used as transit routes to Germany, such as the Netherlands.
Home Office Minister Vernon Coaker is also at Heathrow. His message to any hardcore hooligans still determined to go is: "We're going to stop them. If they do get there, the British and German police will work to stop them causing trouble in Germany."
Commander Bob Broadhurst concedes some may get through, but it is their followers, who wade in to cause widespread trouble, that he wants to stop.
Causes of violence
Banning orders are just one tool in the process. Whether they can help stop violence has been questioned by academics who advise on trouble at football.
Dr Geoff Pearson at the University of Liverpool has said the number of banning orders can be used to overstate their impact - everyone with a banning order might not have travelled.
Social psychologist Clifford Stott, who advises the government on crowd dynamics, says whether violence flares depends more on two factors.
Provocation, for example from hooligans from other countries, and the police response in terms of timing and level of aggression.
Police here at Heathrow recognise that. Commander Broadhurst says: "Part of the role of our officers will be with what we might accept as boisterous support.
"To say 'leave this to us, we can calm this down, we don't need to steam in'."
They expect Friday, the day before England's opening game against Paraguay, to be the peak time for checks. Intelligence indicates 1,100 supporters will travel to Frankfurt on Saturday morning.
It is there, not on the number of arrests in the UK, that they say the operation's success will be judged.