Last season, the French defender questioned the character of his teammates among other things and was stripped of his captaincy privileges by Gunners boss Arsene Wenger.
But after an initial hurting process, Gallas has returned to enjoy some career-best form and Fabregas has confirmed that everything has been put behind them and the players have come together to set up a great title challenge this season.
"We don't think about it anymore and are happy with the way things are going at the moment," Fabregas said.
"The dressing room has always been really together and kept believing.
"Even if we did not win anything last year, we were really close and in all the competitions right until the end, so the mood in the dressing room is always really positive."
The 22-year old also revealed that being captain of such a big club at such a young age has not changed him at all.
"The captaincy hasn't changed me at all," the Spaniard added.
"My team-mates have done a great job for me as well. They showed me they believe and help me with everything.
"There has never been any trouble, so I am very happy with how things are going."