The Gunners have been one of the busiest Premier League clubs this summer following the appointment of Unai Emery as Arsene Wenger’s permanent replacement.
The new Arsenal manager brought in Switzerland international Stephan Lichtsteiner in a free transfer from Juventus.
The north London side snapped up Bayer Leverkusen and Germany goalkeeper Bernd Leno in the current transfer window.
Arsenal improved their defence with Borussia Dortmund centre-half Sokratis Papastathopoulos to bolster Arsene Wenger’s back four.
World Cup star Lucas Torreira was the fourth player to move to the Gunners in a big money deal this summer.
Emery landed his fifth player in the shape of French teenager Matteo Guendouzi to plan for the future.
Former Arsenal striker Hartson believes the Gunners need to sign a leader to further improve their squad ahead of the new season.
Hartson said: “It’s just a rock at the back, a leader of men, somebody to go in there and organise, point the finger at one or two, they’ve failed to bring that type of character in.
“Since the people that I played with when I was there – [Tony] Adams, [Martin] Keown, [Steve] Bould – you don’t see that type of ilk around anymore at Arsenal.”
Arsenal finished in fifth spot in the Premier League table last term.
The Gunners haven’t won the Premier League title since 2003-04 when Arsenal finished the campaign without suffering a defeat.
Arsenal limped out of the Europa League last term following a 2-1 loss to Atletico Madrid in the semi-finals.
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