Mikel Arteta has said discipline is difficult to maintain during international breaks after Arsenal's players were involved in a series of incidents to complicate their preparations for Sunday's Premier League trip to Leeds United.
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Willian is adamant that he did not breach any UK regulations because exemptions are allowed for "business trips."
Pierre-Emerick Aubameyang has suffered a draining week after pictures emerged of the Gabon team having a six-hour wait for a flight in a Gambian airport, forcing players to sleep on the floor after having their passports taken.
When asked in a news conference on Friday whether it was difficult to keep a grip on discipline, Arteta replied: "It is impossible, because we have so many rules and guidelines that we have to follow, that sometimes even without thinking you break them.
"Even in training when you give a bib to somebody else you go: 'Oh no, I cannot do that. The bib has to be here. Someone has to come with the gloves.'
"Sometimes you don't even know [you've broken the rules], so I just try to think that we are all very aware of what we are dealing with and we take it very, very seriously. Everybody can make a mistake, but it is just where that mistake is coming from is the relevant things."
Arteta played down the rift between Ceballos and Luiz, although he did not deny it took place as Ceballos claimed on Twitter, and said that he did not see the incident.
"I have got really bad vision from far, that is why we train behind closed doors," he said. "Training is very competitive and issues happen a lot of times. Those things get resolved immediately within the team and there is not much to say. [There is] no problem at all."
Willian's situation has been dealt with "internally" but Arteta refused to confirm whether the midfielder would be in his matchday squad this weekend.
Arteta was more forthcoming on Aubameyang's travails. Earlier this week, Gabon boss Patrice Neveu said he was concerned Arsenal would not release Aubameyang for future games given the squad's treatment but when asked if that was the case, Arteta replied: "No. Obviously it was a shock to see a full squad sleeping the way they were doing.
"I always believe that everybody is trying to do their best and the Gabon national team are trying to organise things the best possible way.
"Sometimes unpredictable things happen and it was an experience. I said to Auba 'take it as an experience. I'm sure for many months or years you haven't slept on the floor, take it from there and just make sure when you are in your bed, you know how good it is, how comfortable it is and how lucky you are.
"And that's it, you cannot change it, you cannot rewind it, so take it the way it is and move on.' Obviously I hope the next time it doesn't happen and our players have the rest they need."