The 28-year-old Belarusian made 89 league appearances, netting seven times, during a three-year stint in North London.
However, the former Stuttgart star was wowed by the bright lights of Barcelona last summer, joining the Catalans for a deal worth €17 million.
But despite Pep Guardiola's side winning an unprecedented treble in 2008/09, Hleb made just 19 la Liga outings before agreeing to return to former employers Stuttgart on loan.
And the playmaker has admitted that, in hindsight, it was a mistake to leave North London for Catalunya.
"Of course I regret leaving Arsenal," he said.
"I was playing every week for one of the most exciting sides in Europe, a team which was always in the top four in the Premier League and were Champions League contenders.
"I was being guided by one of the best coaches in the world in Arsene Wenger. I owe him a great deal.
"I developed a better all-round game under him and I became more robust physically, learnt to look up more and play better passes and improved greatly as a team player. No player ever gets worse under Wenger.
"Leaving Arsenal was not a good move. Barca were my dream club as a kid, but I couldn't continue with them if the chance to play was not coming."
ARSENAL FANS! Check FourFourTwo.com’s ever-expandinginterviewsarchive for more stuff to read:
Web Exclusives Patrick Vieira, Cesc Fabregas
Q&A Theo Walcott, Cesc Fabregas
One on One Arsene Wenger, Thierry Henry, Ian Wright
Boy's A Bit Special Theo Walcott, Armand Traore
Perfect XI Ian Wright
What Happened Next? Gus Caesar, Peter Marinello
And Another Thing Being a Big Four fan
Plus! Rate Arsenal players (and others) on Talentspotter
