Arsenal have struggled to sell players in recent times, and that has remained the case this summer.They have moved Leandro Trossard and Christian Norgaard on, and also received a bid of €45million (£38.4m; $51.8m) from Galatasaray for winger Gabriel Martinelli.But while the Premier League champions are open to selling the Brazilian forward, is that a fair valuation, or should they hold out for more? And why have they struggled to sell well in the past?After their pursuit of Vinicius Junior ended with him signing a new contract at Real Madrid, how much do they need to upgrade their left wing?Selling youth players has proved profitable for many other Premier League sides and there has been speculation this week over the future of Myles Lewis-Skelly, while his fellow academy graduate Ethan Nwaneri is someone the club are open to selling.Our Arsenal writers Art de Roché, Amy Lawrence and Kaya Kaynak have their say.Why do you think Arsenal have struggled to sell players in recent years?De Roché: There are two factors. Arsenal usually buy players to perform in their peak ages rather than buying young to then sell on. That means when it is time for those guys to leave, the resale value is not there. Alongside that, many players in the past have left Arsenal while on the decline, which does not help either. That is why I was sad but fine with Trossard leaving on a high.Lawrence: How long have we got? It needs more than a paragraph or two to unravel this side of Arsenal’s transfer activity. The impression is very set over a long period of time, so reputationally it is curious to wonder if potential buyers have become accustomed to factoring that into lowball bids. Certainly, there are multiple examples in recent years where it looks as if other top clubs generate fees that outstrip similar talent or experience profiles at Arsenal.That said, the critical flipside to being bad sellers is they are also pretty impressive keepers. Had Arsenal wanted to sell their highest-value players in the past few seasons, you can be sure their record sale would look very different to Alex Oxlade-Chamberlain generating £35million almost a decade ago. However, they consistently retain the likes of Bukayo Saka, Gabriel, William Saliba and Declan Rice — all of whom would surely hit the £100m-plus mark if made available.Arsenal’s record sale is still Alex Oxlade-Chamberlain to Liverpool in 2017 (Dan Mullan/Getty Images)Sporting director Andrea Berta needs to make a big sale or two this summer to rebalance books that are heavily weighted towards purchasing. That’s obvious. You don’t always get to sell the ones you want for the prices you want, which is why some popular names are in the mix now.Kaynak: At times, Arsenal have lacked the decisiveness to move players on, even when the timing is uncomfortable. The one that still springs to mind for me is when Wolves came in for Ainsley Maitland-Niles after he had starred in the 2029-20 FA Cup final. Arsenal turned their offer down and ended up letting him go on a free three years later. That’s just one example, but there have been countless others.I don’t think Mikel Arteta’s selection policies have always helped either. When a player is out of favour under Arteta, they are hardly ever seen. It’s hard to then convince a potential buying club he is worth big money if he’s seemingly not valued by the side doing the selling. A little bit more smart squad rotation would help.In their defence, Arsenal could argue they can be decent sellers after building the value of academy players. Getting the fees they did for Eddie Nketiah, Joe Willock and Emile Smith Rowe look like great business in retrospect.Ultimately, the club haven’t been good enough at building up the value of players they don’t want or moving them on at the right time. It’s time for them to get comfortable with these uncomfortable decisions.How does Bruno Guimaraes fit in at Arsenal?JJ BullShould Martinelli be sold for £40m, a higher fee, or should Arsenal keep him?De Roché: I would sell Martinelli for a higher fee than that, as there is room to improve. Another part of the reason why Arsenal have a reputation as poor sellers is the sums they receive from transfers in comparison to other Premier League clubs. As of last summer, only three teams had lower record sales than that £35million they received from Liverpool for Oxlade-Chamberlain in 2017. With that, and the fact that Martinelli is a Premier League winner with a proven Champions League track record, Arsenal should be asking for more than £40million.Lawrence: No question that fee feels low compared to other wingers on the market. As, indeed, did Trossard’s, considering his output — although it is more complex than a player’s transfer fee alone. Wages, signing-on bonuses, agent fees and so on all inflate a total costing far beyond the club-to-club number.Martinelli’s case, similar to the whispers that have emerged this week around Lewis-Skelly, is an example of moving parts within a labyrinthine beast of a transfer system.For Arsenal, the mission to create their best possible squad for depth and quality requires some upgrades in certain areas, and Berta won’t mind being ruthless if a sacrifice here leads to a new crowning there.There is no world in which everyone stays and expensive marquee signings join. It hurts, particularly when players who are loved move on. The business side has to add up — but common sense must prevail, and Martinelli should not be sold on the cheap.(Michael Regan/Getty Images For Premier League)Kaynak: When you factor in Martinelli’s wages and the length remaining on his contract, a £40million fee does not seem too unreasonable.But you have to then offset it against how much a replacement would cost. When you look at what wingers have been going for this summer, you assume it would be considerably more than £40m. So with that in mind, you have to try to get more money.If you can’t, then you might as well keep him. He has been frustrating in front of goal at times, but he is a popular member of the squad who has proved himself to be a high performer in big games. Getting rid needs to be for the right price.What are your views on selling academy graduates such as Lewis-Skelly and Nwaneri?De Roché: Arsenal have acknowledged their best sales in recent years have come via their academy. Willock leaving for £25million opened the door for Martin Odegaard to join in 2021, while the departures of Smith Rowe (£34m), Alex Iwobi (£34m) and Nketiah (£30m) are the only ones that rival the Oxlade-Chamberlain fee.That being said, it is hard to see the logic in selling either Lewis-Skelly or Nwaneri in favour of new arrivals who would mean less to the club and its fans. Especially when they both have qualities that are rare in any Premier League team, let alone Arsenal.Lawrence: As Art points out, it is homegrown sales that have proved most fruitful. They are also painful — extremely so when the connection between player and supporter is rooted in shared values and identity that money can’t buy.But this is where the specialist mindset of a manager or deal-maker comes to the fore. They have to think business and be ruthless. Fans will always react with their hearts, and rightly so.Lewis-Skelly scored against Como on Wednesday (Stuart MacFarlane/Arsenal FC via Getty Images)There is a difference in the cases of Lewis-Skelly and Nwaneri, in that the former has been far more involved in some monumental moments. It is possibly easier to justify making pure profit on Nwaneri as his situation is less established. Lower down the age range are Max Dowman and Marli Salmon, who would be snapped up for big money in a heartbeat but are off-limits.Ideally, both Lewis-Skelly and Nwaneri stay and funds are generated by high-fee sales for more expendable players — the likes of Gabriel Jesus, Fabio Vieira and Reiss Nelson — but that is not realistic.Kaynak: This is tricky. Arteta has shown he’s unwilling to provide opportunities to academy players who aren’t at the level he demands. But Lewis-Skelly and Nwaneri have proved they are.Lewis-Skelly was arguably man of the match in May’s Champions League final, while Nwaneri nearly hit double figures for goals in his first proper season with the first team in 2024-25.Both provide qualities this Arsenal squad are lacking, and if it were up to me, I would have them backing up the more established stars in Saka, Odegaard and Rice. Arsenal, though, have gone in a different direction, signing expensive options in those positions who have created a logjam ahead of their Hale End academy boys.I would have preferred for that blockage not to have been created in the first place, but with things as they are, you have to seriously consider selling these players while their values are high. Another season of limited minutes and the potential for a big sale could plummet.Should Arsenal sell to upgrade the left-wing position or stick with what they have?De Roché: If they receive a significantly stronger offer for Martinelli than Galatasaray’s opening bid of £38.4million, they should look to sell and upgrade. That does feel like it would require more interest in him from clubs in bigger leagues, however, as Martinelli going to Turkey at 25 years old is very different to Trossard doing so at 31 earlier in this window.If it gets near to deadline day, maybe Arsenal should bite the bullet and accept whatever is on the table. They could activate the option in Martinelli’s contract to avoid losing him on a free next summer, but it may be better to make a definitive decision.If they fail to replace him, Eberechi Eze can support new signing Christos Tzolis on the left wing, which could free up opportunities for the squad’s many other central midfielders.Christos Tzolis has joined from Club Brugge (Alex Caparros/Getty Images)Lawrence: It is clear that Arteta expects a serious injection of quality in attack this season. The attempt to recruit Vinicius Jr demonstrates the intention. The left wing appears to be a priority position, but if the required calibre to be a difference-maker is not available, sightlines may be shifting to a more central area. Julian Alvarez, until his situation at Atletico Madrid is resolved, remains worth watching.Kaynak: I think it depends on who the upgrade is. If you’re signing Vinicius Jr, then definitely! I think Arsenal’s willingness to offer him the world to make a deal happen suggests they agreed. That isn’t going to happen, though, and if you look at the other options right now, there aren’t many obvious upgrades.A refresh was needed on the left wing, but Arsenal have arguably already got that in Tzolis. If they can’t find a huge improvement on Martinelli, I would be fine with waiting another year.It’s important to sign the right player, rather than just getting somebody through the door.