There were a couple of departures we are sure Arsenal were upset about last season - but ones almost out of their control.
Robin Van Persie for instance. It was sell or lose him for nothing at the end of the season - the Dutchman had to go.
Alex Song also made it clear he wanted to leave. Why keep an unhappy player when Barca come knocking? They had to sell the Cameroonian as well.
But one other player is surely their biggest regret of last summer, because they actively let him leave the club.
When Arsenal allowed Mexican international striker Carlos Vela join Real Sociedad on a permanent deal last summer - we doubt they considered he would be being lined up as a replacement for Robert Lewandowski at Borussia Dortmund a little over a year later.
Arsenal were left to rue their impatience on Vela last season, as he fired Real Sociedad into an unlikely Champions League spot in La Liga. It was such impressive form that The Gunners were even reported to be considering utilising a buy-back clause in his deal at San Sebastian - but Vela made it clear he was going nowhere.
He scored 14 goals in 38 appearances for the Basque club last season, and also added nine assists to that tally.
This year the player has been in good form again, scoring four and setting up two in his five games in 2013-14 so far - and now it looks as if he is going to be tasked with replacing Lewandowski at Borussia Dortmund.
Reports in Spain have recently been talking of interest in bringing in Vela at the end of the season - and today it is reported if Sociedad go out of the Champions League at the Group Stage he could end up in the Bundesliga as early as January.
Not bad for a player Arsenal practically gave away last summer.
Do you think letting Vela leave was a mistake from Arsenal?
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