The Gunners added three new faces to a squad that was badly in need of reinforcements if they were to maintain their unlikely challenge for the Premier League title.
Defender Jakub Kiwior will offer a viable alternative to Gabriel Magalhaes, who has started every league game so far this season, while deadline day recruit Jorginho will bolster a midfield department that was increasingly reliant on Thomas Partey and Granit Xhaka.
Arsenal had, meanwhile, intended to break their transfer record in order to sign Mykhailo Mudryk from Shakhtar Donetsk but were beaten to the punch by Chelsea who hijacked the deal.
Mikel Arteta swiftly turned his attention to Belgium international Trossard, but former Arsenal skipper Gallas is worried that the former Brighton star may struggle with the demands of representing a far bigger club.
He told gentingcasino: ‘I don’t know if Leandro Trossard is a good signing. He has a big profile like his fellow teammates but the question is, can he lift his level at a big club?
‘If it’s a good signing, he will help take Arsenal to victory. When you bring players to a big club, they have to play really well, so we need to wait and see what happens.’