Dixon, a member of Wenger's 1998 Double winners, told the Daily Star Sunday: "It was an awkward subject to approach but I pulled aside Arsene at the training ground because I wanted him to tell me about the captaincy.
"I thought there might have been a change and had been critical of Gallas as a captain and leader.
"Basically, Arsene said that Gallas is a great defender - but is also one of those players that: 'If I had taken the captaincy from him, I might have lost him as it could have affected him'.
"I said the flip side to that is then he surely isn't the right man for the job - if he is going to sulk or not do his job on the pitch just because you take something away.
"But Arsene said the position of the club at that particular time - at the start of the season - meant there wasn't any natural person to take over.
"And that's why they were going with Gallas and had to get on with it."