Unai Emery begins the task of steering Arsenal into a brave new post-Arsene Wenger world.
Arsenal manager Arsene Wenger has confirmed that Mesut Ozil faces around six weeks out with a knee ligament injury, a problem that was only discovered when the midfielder joined up with the Germany squad for international duty last week.
Here are five talking points from the weekend's action:
Manchester City withdrew from the battle to secure the services of Arsenal's Chilean forward Alexis Sanchez, leaving Jose Mourinho's Manchester United as the most likely destination for the 29-year-old.
Czech Republic goalkeeper Petr Cech ended a highly successful 11-year spell at English champions Chelsea when he moved to Premier League rivals Arsenal on Monday.
Alexis Sanchez grabbed a 15-minute hat-trick as Arsenal shook off any hangover from their midweek League Cup defeat to thrash West Ham United 5-1 and climb to second in the English Premier League.
IMAGES from an exciting Europa League semi-final first leg match played at Emirates Stadium on Thursday
Images from Sunday's English Premier League matches.
Heavyweights Arsenal, Atletico Madrid and Lazio took big steps towards reaching the Europa League semi-finals after convincing home first-leg victories and RB Leipzig also stayed on course with a 1-0 win over Olympique de Marseille on Thursday.
'You have to have a good coach to direct you on the right path.' 'I had Arsene and Pep in my professional career, but I was lucky to have good coaches in my younger days.'
Arsenal scored twice in three minutes through a deflected Granit Xhaka strike and Danny Welbeck's header to claim a deserved 2-0 win over Manchester United on Sunday and inflict a first Premier League defeat on the visitors in 26 games.
The result leaves Ole Gunnar Solskjaer's United in 10th with nine points, their worst start after seven games for 30 years, and they have won just one of their last six league games.
Images from the English Premier League matches played across England on Sunday.
Henry, who started out playing for Monaco and went on to enjoy a stellar club career with Arsenal and Barcelona, has been working as assistant coach for the Belgian national team but has never been in charge of a team in his own right.
Arsenal will begin their quest to become the first team in modern times to win the FA Cup three years running with a home tie against fellow Premier League side Sunderland in January.
The 28-year-old, who joined Arsenal in 2006, scored 108 goals in 397 appearances but has struggled to hold down a first-team place this season under manager Arsene Wenger.
After damaging losses to Dinamo Zagreb and Olympiakos Piraeus in their first two fixtures, the Gunners have to win to advance to the knock-out stages
This and more from the happenings in the world of football
England under-21 coach Gareth Southgate looks likely to be put in temporary charge of the national team after the resignation of Roy Hodgson following the side's Euro 2016 exit, British media reported on Wednesday.
With no Champions League football for a third straight season, the financial realities are starting to bite and Arsenal will be desperate for some of their talented youngsters to come through.
Out-of-sorts Chelsea have a golden opportunity to restore battered self-confidence when they face Maccabi Tel Aviv in their opening Champions League Group G match.
United beat Leicester City at Old Trafford in the opening game of the season but Spurs present a very different quality of opponent.
News of all that's transpired on and off the football field
'I think it's unacceptable what he does to Koscielny. He pushes him down, he hits him in the face. I do not understand Mike Dean's decision at all. Why does Diego Costa stay on the pitch and Gabriel is sent off?' 'If you want to speak about Diego Costa with me, it's just to say he played like he has to play and that's why you have full stadiums, you sell to television around the world for millions and millions because the game has to be played like that'
News of all that's transpired on and off the football field
A summary of Tuesday's League Cup matches.
News of all that's transpired on and off the football field
Holders Arsenal kept up their bid for a hat-trick of FA Cup trophies, marching into the quarter-finals as Olivier Giroud and Theo Walcott netted twice in a 4-0 replay win at second-tier Hull City on Tuesday.
Alex Ferguson famously described the Premier League title run-in as 'squeaky-bum time' and leaders Leicester City and second-placed Tottenham Hotspur look best-placed to handle the pressure.
If Arsenal are to have any chance of overturning a 2-0 deficit against Barcelona in the Champions League next month they must be sharper in front of goal, says manager Arsene Wenger. They worked hard to keep the world's most fearsome attacking trio of Lionel Messi, Luis Suarez and Neymar relatively quiet until the 71st minute of Tuesday's last 16, first-leg tie but by then they had spurned two excellent chances to take the lead. Alex Oxlade-Chamberlain was the culprit in the first half, anxiously shooting straight at Barcelona goalkeeper Marc-Andre ter Stegen, then Frenchman Olivier Giroud failed to convert the kind of close-range header he regularly dispatches. They are the sort of opportunitites that must be taken in the return at the Nou Camp on March 16 when Arsenal face what many pundits think is 'mission impossible' after Messi showed how it should be done with two late goals at The Emirates. The Argentine's first strike followed a clinical counter-attack and his second from the penalty spot in the 83rd came after he was brought down by substitute Mathieu Flamini. "We had an unbelievable chance in the first half and the way we finished our chances is a problem," Wenger told reporters after his side's demoralising defeat.
Champions Chelsea have not enjoyed the best of starts at home this season and face their biggest test yet on Saturday with the visit of free-scoring leaders Manchester City.
Leicester City will be wary of a reality check when the Premier League front-runners visit Arsenal on Sunday before Tottenham Hotspur's burgeoning title ambitions come under scrutiny at Manchester City.
Marcus Rashford scored twice as holders Manchester United brushed aside second-tier Burton Albion 4-1 at Old Trafford to reach the fourth round of the League Cup on Wednesday.
News of all that's transpired on and off the football field
Lionel Messi has become the first player to win Europe's Golden Shoe award for three straight years after his nearest challenger Kylian Mbappe failed to score the four goals he needed in Paris St Germain's final league match of the season on Friday.
A downbeat Arsene Wenger said he has decided on his Arsenal future and would reveal all soon after his side slumped to a dismal 3-1 defeat at West Bromwich Albion on Saturday.
Wenger dropped Rob Holding for the visit to Stoke, preferring Shkodran Mustafi alongside Nacho Monreal and Sead Kolasinac at the back.
Arsene Wenger acknowledged Southampton were the sharper team as they crushed Arsenal 4-0 on Saturday but he also blamed the defeat on bad luck.
Arsenal's record signing Mesut Ozil has not got over his penalty miss in the Champions League loss to Bayern Munich, manager Arsene Wenger said before backing his side to bounce back strongly against Sunderland on Saturday.
Arsenal will put one of the best Champions League records on the line when they face Olympiakos Piraeus in a showdown for second spot in Group F on Wednesday.