Arsenal can win the treble this season according to Alex Hleb, who says his time at the club was the best of his career.
The Belarus star spent three seasons with the Gunners, reaching the Champions League final in 2006 and coming within four points of the Premier League title two years later.
And Hleb believes Arsene Wenger's current side have shown the early-season potential to go the distance and win both competitions come next spring.
"Wenger always sets the highest goals," said the 35-year-old, still part of the Belarus international side. "He has managed to keep his key players and they are playing great football. They are tearing everyone apart.
"I hope the team will win three trophies this season - the Premier League, the FA Cup and the Champions League. This Arsenal side certainly has the ability and I will really be supporting them."
Hleb left for Barcelona in 2008 but failed to make an impact under Pep Guardiola and spent three of his four years at the club out on loan.
"I was playing at the top of my game in London and it was the best moments of my career," he said.
"On the one hand, I regret that I did not stay at Arsenal. Wenger was like a father to me and trusted me. I get sad when I start to think about this.
"On the other hand, Barcelona was and still is the strongest club. I did not play that often, but I still got game-time."
Hleb admits he "should have behaved more professionally" at Barca but said: "If Wenger had been in [Guardiola's] place, he would have come up to me and talked to me.
"I think he is a great. I remember Jens Lehmann used to record how Wenger took training every day. I also wanted to do the same, but I thought, 'I will still have time as I am under contract for a long time'..."