Arsenal suffered their first defeat of the season on Saturday, beaten 3-0 away at Brighton, and the mood around the club has been further rocked by news that one of Mikel Arteta's marquee signings is now pushing to leave.

Arteta challenges Arsenal to learn from Brighton defeat

Arteta didn't hide from how difficult a night it was at the Amex, praising Brighton's sharpness while stressing there were lessons to be learned.

"Firstly, because Brighton were really good, they had another bite and their timing was better," the Spaniard said when asked to explain the Gunners' lacklustre performance.

"There are a lot of moments when the ball is 50/50 and it changes hands, and most of the time it was for them. They opened us up in a really difficult way, that's something to learn.

"That's not going to take away what this team has done, and what the boys have done in the last six or seven weeks since coming back from the World Cup, because with 18 players coming back, the way we've competed and the number of games we have won has been remarkable. But this is a big lesson on what it takes to win at this level."

The Arsenal boss also admitted something felt wrong with his side from the very start.

Gyokeres wants to leave Arsenal on loan

Adding to the sense of unease, FourFourTwo report that Viktor Gyokeres is now edging towards a January exit, with the Swede growing increasingly frustrated by a lack of game time under Arteta this season.

The striker is said to be in talks with Milan over a possible move, with the Rossoneri weighing up an approach for the centre-forward after Goncalo Ramos has struggled to make an impact since his summer arrival.

Crucially, it's claimed Gyokeres wants to leave on loan just to start playing regularly again - meaning Arsenal could effectively lose him for nothing in the short term, despite paying in the region of £55m plus a further £8.5m in add-ons to sign him from Sporting last summer.

It's a striking fall from grace for a player who arrived with such fanfare. Gyokeres' minutes have been increasingly hard to come by in recent weeks, reduced to a fringe role off the bench with just two appearances in the top flight so far this term.

With Kai Havertz having established himself as Arteta's preferred central striker and Mikel Merino also offering an option through the middle, Gyokeres finds himself down the pecking order despite scoring 21 goals in all competitions last season as Arsenal won the Premier League and reached the Champions League final.

Which strikers could Arsenal sign?

Should he leave in January, it would leave Arsenal short up front once again, having already lost Gabriel Jesus, Gabriel Martinelli and Leandro Trossard from their attacking ranks over the summer with only Christos Tzolis coming in as a replacement.

The Gunners are already believed to be keen to strengthen further in the New Year as a result, and while Julian Alvarez has been strongly linked as a potential option, reports suggest Arsenal may instead look at Maximilian Beier, who they are understood to have scouted extensively over the past year.

The 23 year-old Borussia Dortmund star, who can play numerous positions in attack, has scored once and provided two assists in four Bundesliga appearances so far this season.