In the past, the Crows players have voted on both the captaincy and leadership group just before the Christmas break, but Harper said the vote would be split this year to give the players more time to choose a successor for retired skipper Simon Goodwin.
"The players will probably know before Christmas who they want to be in the leadership group, but they won’t vote for the captain until after Christmas," Harper told afc.com.au.
"The idea is just to give the guys a bit more time to make 100 per cent sure they know who they want to be their captain."
Reliable midfielder Nathan van Berlo was considered an overwhelming favourite to become skipper when Goodwin announced his plans to retire in May, but Harper said several other players had stepped up to help fill the leadership void left by retired veterans Goodwin, Tyson Edwards, Andrew McLeod and Brett Burton.
"There are a lot of people putting their hands up to show their leadership qualities," Harper said.
"I don't think it was ever clear-cut [with van Berlo]. There are obviously some favourites there, but we just want everyone to have ample time to put their case forward."
Tough onballer Scott Thompson is one such player pressing his claim for the captaincy.
Thompson oozes onfield leadership, but prior to this pre-season hadn't showed an interest in developing the all-round package that would allow him to be part of the leadership group, let alone to captain the club.
The 27-year-old has made a conscious effort to be more involved this off-season and his efforts haven't gone unnoticed, with Patrick Dangerfield identifying him as potential captaincy material during the recent tour of Ireland with the International Rules team.
Utility Jared Petrenko has joined in the chorus of support for Thompson, saying the former Melbourne midfielder was a genuine chance to come from outside last season's leadership group to lead the team next season.
"When Goody said he was going to retire I always thought the captaincy would go to VB [van Berlo], but without Goody, Andrew McLeod and the older boys there guys like Thommo and Ben Rutten are putting their two cents in," Petrenko said.
"Thommo has been really impressive, so it's shaping as a really tough vote but I think we'll be in good hands no matter who gets the captaincy."
Dangerfield and gutsy onballer Rory Sloane are also likely to be included in the leadership group for the first time when the votes are cast later this month.
The two natural leaders have increased their physical and vocal presence at training and Petrenko said the possible inclusion of the two 20-year-olds would reflect the changing face of the playing list.
"Patty has showed leadership ever since he arrived at the club and there's no doubt that he'll be in the leadership group, if not next year then in the years to come, and the same with Rory," he said.
Adelaide's leadership group last season was Goodwin, Brett Burton, Michael Doughty, Scott Stevens, Nathan van Berlo, Brad Symes, Ben Rutten and Tyson Edwards, who was later replaced by Ivan Maric.
