It emerged this week that Matthews is on a ticket that will challenge current chairman Angus Johnson.
Earlier this month the Lions made the stunning decision to sack coach Michael Voss.
Board spill may affect coach hunt
That immediately led to speculation they had lined up Roos to take over.
"Paul Roos is the top of everyone's list, but I think the chances of Paul Roos coaching Brisbane are about nil," Matthews told 3AW.
Matthews, who coached the Lions to their three straight premierships a decade ago, also stressed his only potential role at the club would be as a board member.
"I'm not going to be chairman. I'm not going to be CEO. I'm not going to be coach," he said.
"Two people that I know well who that are currently on the Brisbane Lions board, had decided that they were going to challenge for the chairmanship and the deputy chairmanship.
"They came to me and said we'd like to do this.
"They asked me if I would come on as the football person on the board which I agreed to.
"That's it in a nutshell basically."
That immediately led to speculation they had lined up Roos to take over.
"Paul Roos is the top of everyone's list, but I think the chances of Paul Roos coaching Brisbane are about nil," Matthews told 3AW.
Matthews, who coached the Lions to their three straight premierships a decade ago, also stressed his only potential role at the club would be as a board member.
"I'm not going to be chairman. I'm not going to be CEO. I'm not going to be coach," he said.
"Two people that I know well who that are currently on the Brisbane Lions board, had decided that they were going to challenge for the chairmanship and the deputy chairmanship.
"They came to me and said we'd like to do this.
"They asked me if I would come on as the football person on the board which I agreed to.
"That's it in a nutshell basically."
