Mikel Arteta has warned Arsenal must be "very careful" over who they sell in the final days of the transfer window.
The Gunners have invested significantly over the past 12 months, spending more than £250million last summer and bringing in barely £10m in sales.
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There has been a greater focus on finding the right balance during this window, though outgoings have proved difficult.
After sensing there was no significant market for Reiss Nelson, Arsenal made the decision to terminate his contract by mutual agreement to save on his wages.
Gabriel Martinelli is the big summer departure, with Arsenal signing off on a club-record sale to Al-Hilal.
Gabriel Jesus and Fabio Vieira could also leave before the window shuts on Tuesday night.
Arteta confirmed that Arsenal are still pursuing a self-sustaining model, but emphasised that did not mean making sales that were not in the club's best interest.
"That's what we are trying to get as a club but the balance has to be right," Arteta said.
“There are areas that we have to improve to hit those numbers. And if it's not with sales, because maybe we don't want... We have to sell what we want to sell as well, not just to sell.
"And then when we want to sell as well, we have to be very careful because some of the assets, after maybe they grow and we still want them.
“So maybe we can grow in other areas across the club as well. And commercially, we've done incredible. The fan base that we have is incredible. Our mass revenue is incredible. And there are other ways to grow and that’s the club's strategy.
“But we want to improve in all of them, obviously, because it's going to give us a bigger room to be stronger financially."
The size of Arsenal's squad means that Arteta will have to leave players out of his 20-man matchday squad against Aston Villa on Monday night.
Arteta reiterated that message again, urging his "really, really simple solution" to be implemented.
“Yeah, that's why I've been begging the Premier League if we can extend those numbers just for the welfare of the players, which is the most important thing," Arteta said.
"Because I think every squad needs more than 20 outfield players, ideally, to sustain the level of demand in international games that we have.
“But these are the rules, and within the rules, we have to play. Otherwise, we will play tennis. You are guaranteed that tomorrow you're going to play and [even if] you don't like yourself, unfortunately, the next day you have to play again. So we need to take it naturally.
We have to be very careful because some of the assets, after maybe they grow and we still want them
Mikel Arteta
“Obviously, we need to be very close to the players to explain those situations in the right way, for everybody to feel important, because they will be.
“And all the clubs, because I've done the research with all the top clubs in Europe, we are not different to anybody. Most of them, 90% of them, they have more players than us. So we are going to have to deal with that.”
He added: “Otherwise, you have to tell somebody you are not even part of this matchday. And that's really, really tough.
"It doesn't help anybody. It doesn't help the club. It doesn't help the valuation of the player. It doesn't help feel the player that feels part of something. It's, in my opinion, a real issue that has a really, really simple solution.”
