But with the Demons announcing that Trengove is to miss two weeks with a strained calf and Grimes now on the long-term injury list, Jones will be the solo leader against Gold Coast and Richmond.
Defender Colin Garland has been elevated to the role of acting vice-captain.
In announcing the "added levels of leadership" for Jones and Garland on Thursday, embattled Melbourne coach Mark Neeld was again forced to explain why Trengove and Grimes were given the captaincy at the start of the 2012 and more to the point, why Jones was not.
He said the club took its time to make the decision, which was based on the "actions and behaviours" of the playing group at the club.
"When all the boys' peers sat down, for two years in a row, Jack and 'Grimesy' have been the two at the top of the tree," Neeld said.
"Nathan and Colin have shown significant leadership improvement, but Jack Grimes and Jack Trengove are the two best leaders on our playing list. That's where it is at."
When pressed on why Jones, last year's best and fairest and clearly the best player so far this year, had been overlooked in the past, Neeld again made his point, albeit with a touch more irritation.
"I fail to see why someone was running third you would elevate him to one. I don't get it.
"Jack's leadership is sensational. To the people who deal with those guys every day, they are clearly the best leaders on our playing list," he said.
Neeld, who laughed off suggestions that former Sydney Swans premiership coach Paul Roos had been earmarked to take his job, said the Demons were under little pressure against fellow stragglers Gold Coast at the MCG on Sunday.
"We will have less experience than they will," he said. "We will have 14 players with less than 50 games of football."
Former Collingwood forward Chris Dawes will make his long-awaited debut for the Demons this weekend.
Ashley Browne is an AFL Media senior writer. @afl_hashbrowne
