It ended in the fourth round, here on the south coast, with something of a whimper as Southampton claimed a 1-0 victory.
Unlike Arsenal, they named a full-strength team and, when you saw the two XIs before kick-off, immediately became favourites.
Under Ralph Hasenhuttl, they have become a slick and well-oiled machine and we saw that today. Southampton only won by a solitary goal but, particularly in the first half, they could have doubled or tripled that lead.
Arsenal, in contrast, were rusty and sloppy. That was largely down to personnel, with Arteta handing minutes to those who needed them.
Gabriel Magalhaes was a prime example. The defender has not played for a month since testing positive for Covid-19 and it showed.
He has been excellent this season since signing from Lille, but his passing was off today and his own goal summed up his afternoon.
It was the same story in attack. Arteta completely changed his front four from the win over Newcastle on Monday and paid the price.
Willian, as he has been all season, was a passenger and the game seemed to pass him. Nicolas Pepe was similarly ineffective in the first half, although he perked up after the break and almost made the difference.
Then there was Eddie Nketiah, who last season looked like a player possibly capable of displacing Alexandre Lacazette, but now you doubt that. He struggled against Southampton and, with no more cup games, you wonder when his next chance will be.
In fairness, the same could be said for a lot of players handed a start today.
Rusty Gabriel may struggle to regain place
He has been a shining light for large parts this season, but Gabriel had a torrid afternoon on the south coast. It started minutes into the game, when the ball squirmed under his foot and out for a throw-in, and it didn’t get much better.
Usually so calm and composed on the ball, the Brazilian looked rusty and it showed how being out of the team for a month has impacted him. The challenge now is getting him back up to speed, but Arteta can at least feel safe in the knowledge he has plenty of options.
In Gabriel’s absence, Pablo Mari has excelled - while more recently David Luiz has looked solid too. They have helped Arsenal, before today, keep five clean sheets in a row.
And, with the season being so manic and fast paced, you wonder if Gabriel may now face a fight to get back in the side.
Partey and Saka cameos bode well
If there was some positivity for Arteta to take from this loss, it was the impact of his substitutes. Bukayo Saka and Thomas Partey came off the bench with 30 minutes to go and almost made the difference.
They were a level above everyone else on the pitch and they should give Arteta confidence going into Tuesday’s rematch with Southampton in the Premier League. Saints went full strength here in the Cup and - if they do so again in midweek - Arsenal should back themselves to be fitter and fresher.
Time will tell, but Arteta will hope his rotation gamble has paid off.