Going into the World Cup break, morale was sky high in the red half of north London with Arsenal sitting five points clear at the top of the Premier League table.
While that fact remains the same, Arsenal could be going into the second half of the league season without an integral part of their squad in talismanic forward Gabriel Jesus. The £45million former Manchester City man has sustained an injury while away at the tournament with Brazil.
It is a clear case of every club manager's worst nightmare, with a star player jetting off on international duty mid-season before returning injured and unavailble. News first broke of Jesus suffering some kind of problem with his right knee that would initially see him ruled out for three weeks.
Though that timeline would immediately end his hopes of participating in the rest of the tournament with the Selecao, it meant he'd be back in time for Arsenal's hectic festive period, perhaps with the exemption of West Ham's trip to the Emirates on Boxing Day.
However, disaster appears to have struck, with fresher reports claiming Jesus will now need to undergo knee surgery which in turn will keep the 25-year-old out of action for as long as three months - sparking new doubts over Arsenal's title credentials.
The Gunners have been in a similar position before back in 2007/08.
Then guided by Arsene Wenger, a young Arsenal side were vying for the title and sat two points clear in February before forward Eduardo da Silva suffered a horrendous tibia and fibula fracture that was so gruesome television cameras were banned from showing any replays of the incident.
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It would be disingenuous to claim Eduardo played quite as big a role in that Arsenal team as Jesus does in this one, but the emotional impact of losing a key man while top of the table with pressure sky-high took its toll on an inexperienced squad that capitulated in the latter stages.
Three successive draws after the game that saw Eduardo sustain his injury all but ended the Gunners' hopes of a fourth Premier League title and they eventually finished third.
This current Arsenal side are the youngest in the Premier League by some distance and while they have already proven they can be resilient in the face of tough opposition, it remains to be seen how they would respond to losing arguably the most important player in their squad for an extended period of time.
Jesus is expected to touch back down on English soil on Sunday before heading to Arsenal's London Colney training base where he will undergo tests to determine the severity of his injury.
There has been some rumours suggesting Jesus has actually been carrying this issue since long before the World Cup, but played through the pain barrier for both club and country until it eventually got the better of him.
Everyone associated with the Gunners will be anxiously waiting for an update on Jesus' fitness, but if going under the knife turns out to be the only option Arsenal may have to reassess their ambitions this term.
