Former Arsenal player Paul Merson (Picture: Sky Sports) Paul Merson believes that Arsenal’s decision to sell Gabriel Martinelli will hold them back from winning the Champions League this season. Martinelli’s move to Saudi Pro League side Al Hilal was confirmed on Thursday, with the Brazilian winger joining for a fee of £60million. That figure marks a club-record sale for the Gunners, who also let Leandro Trossard depart for Besiktas earlier in the summer. Arsenal brought in Christos Tzolis from Club Brugge as a replacement, but the defending champions ultimately failed in their bid to sign a marquee left winger in the summer window. Exclusive Premier League previews Get ahead of the start of the season with our weekly football newsletter. Sign up now for free. Morgan Rogers was a key target for Mikel Arteta but instead chose to join Chelsea, while Vinicius Junior opted to extend his contract at Real Madridafter interest from the Gunners. And while Merson believes Arsenal are still the team to beat in the league, the former Gunners midfielder thinks their transfer business in forward areas could cost them when they face the elite sides on the continent. ‘I think they’ll win the Premier League, but I think they’ll fall short in the Champions League because of not having that extra person up front,’ Merson told Sky Sports. Gabriel Martinelli’s departure to Al Hilal was confirmed on Thursday (Picture: Getty) ‘Havertz and Gyokeres, I like those two, but they are not going to give you sleepless nights. ‘And you look on the left, you have Tzolis and Eze. Eze is a good footballer, but I think I like him more in the middle than out on the left and Tzolis is a very hard-working left winger, a manager’s dream. ‘My picture is when you’re playing against PSG away and Bayern Munich away and Inter Milan away and Real Madrid and Barcelona, I can’t imagine the right-back having a sleepless night. ‘I can’t imagine him tossing and turning in bed thinking, oh my god, I’ve got to play against him tonight.’ Chistos Tzolis was signed to replace Leandro Trossard and Gabriel Martinelli (Picture: Getty) Merson continued: ‘I wouldn’t have let Trossard go, in my opinion, I think he’s a good footballer. I think he’s a clever player and has played in the big games. ‘When you’re at the top, you buy players, you buy players and you stay at the top. The thing with what you’re saying about Arsenal’s forward line and the players they’ve got in their position, they’re very good in the Premier League, because teams sit back against Arsenal in the Premier League, so they haven’t got any runners. ‘No one runs off the ball, Arsenal, the front players; you never see them going that way. But they’re alright, because teams sit ten behind the ball and they’ll have the guile and they’ll have the patience to break a team down. ‘When you go and play PSG away and Bayern Munich away and they come and have a go at you, they won’t have that fear of that pace of Martinelli on the counter-attack, and that will cost them.’ Arsenal incoming and outgoings INCOMINGS Guimaraes put pen to paper on a four-year deal in north London (Picture: Getty) Bruno Guimaraes (Newcastle) – £75m Ezri Konsa (Aston Villa) – £51m Piero Hincapie (Bayer Leverkusen) – £35m Christos Tzolis (Club Brugge) – £34m Illan Meslier (Leeds) – free transfer OUTGOINGS Trossard ended his stay with the Gunners to join Besiktas (Picture: Getty) Gabriel Martinelli (Al-Hilal) – £56m Leandro Trossard (Besiktas) – £17m Jakub Kiwior (Porto) – £14.8m Gabriel Jesus (Barcelona) – £8.6m Fabio Vieira (Hamburg) – £8.6m Christian Norgaard (Everton) – £7m Speaking earlier in the week, Arteta insisted Arsenal had no regrets about their decision to sell Martinelli and Trossard after failing to sign another attacker in the latter stages of the window. ‘The selling of players can come from different aspects as well,’ the Spaniard said. ‘It’s not always the same one. That’s part of the responsibility we have at the football club. ‘I unde