The Whites were 4-0 down at one stage before mounting something of a comeback, but for the most part, this was a rare misstep for Marcelo Bielsa and his side.
In particular, Leeds struggled to live with the constant threat posed by young talent Bukayo Saka, so much so that former Elland Road stopper Paul Robinson believes that the trip to the Emirates could have lasting consequences for the man tasked with keeping the 19-year-old quiet.
Speaking to MOT Leeds News, the ex-England number one said: “I think [Gianni] Alioski was exposed again for his defensive frailties.
“Leeds’ need for a left-back is getting more and more apparent.
“You saw when Alioski walked off the pitch, he looked really dejected and he had a long walk around the pitch. He did his best to avoid Pepe as well on his way round after what happened at Elland Road.
“Leeds will buy a recognised left-back in the summer and that could force Alioski to look elsewhere with his contract coming up.
“There’s no word on his contract situation and getting subbed off like that and Huggins coming on and doing excellently… it doesn’t bode well for him at the moment.”
The stats back up Robinson’s criticisms too.
As per Whoscored, Alioski made just one tackle against Arsenal – a notable decrease on the five he managed against Crystal Palace just a few days earlier.
Likewise, he registered no clearances and and won 0% of his aerial duels, while Saka made 10 attempted dribbles – nearly double his season average of 5.13, as per Wyscout.
It was certainly an afternoon to forget for Alioski.
Elsewhere, Leeds forward Rafa Mujica has made a flying start to life with new team Las Palmas.
The Spaniard joined the Gran Canaria outfit on loan in January, and according to AS, has hit the ground running.
Mujica scored on his second outing for the club, and the Spanish outlet suggested that he put in an “outstanding” shift.
La Provincia back that view up, and they now suggested he has 17 games to earn himself a permanent move.
So far, so good on that front for the 22-year-old...
1. Mujica off to flying start
Leeds United forward Rafa Mujica has made a good start to life on loan at Las Palmas. The Spaniard impressed on his debut in Gran Canaria and has until the end of teh season to convince his new side to make his move permanent. (AS) (Photo by Dean Mouhtaropoulos/Getty Images) Photo: Dean Mouhtaropoulos
2. Alioski could leave in the summer - Robinson
Gianni Alioski could be forced to leave Leeds United in the summer following his subpar performance against Arsenal on Sunday, according to Paul Robinson. (MOT Leeds News) (Photo by Catherine Ivill/Getty Images) Photo: Catherine Ivill
3. Barton in advanced talks
Former Newcastle United midfielder Joey Barton is in advanced talks to land the vacant manager's job at Bristol Rovers. (Football Insider) (Photo by Pete Norton/Getty Images) Photo: Pete Norton
4. Greenwood signs new deal
Mason Greenwood has signed a new long-term deal with Manchester United, and will stay at the club until at least 2025. (Official club website) (Photo by Michael Steele/Getty Images) Photo: Michael Steele