He was signed for £350,000 in the summer of 2005, from Atalanta, after the club agreed a compensation fee for the youngster, who had yet to sign a professional contract.
He made his debut for the club in a friendly against Barnet, but has not featured in a competitive match for the Gunners.
In August 2006, Mannone was loaned out to Championship side Barnsley, where he made a horrific error on his debut, gifting a goal to Preston after Nick Colgan had been sent off.
His next match for the club did not get much better, as he dropped a cross late on and allowed Luton to score the winner.
Injury cut his loan short, and he returned to Arsenal for treatment on his knee. He had been rumoured to go out on loan again in the 2007/08 season, but failed to find a club to guarantee him first-team football.
After returning to Arsenal the stopper made eight starts for the second string. The highlights of his season included a superb performance in a 2-2 draw with Reserve League South champions Reading and a fine penalty save in a 1-0 defeat to Watford.
