Buchanan, who is the Rams' longest-serving current player, will represent the club at off-field events and functions, while Spaven will lead the team on the field.
"Having two captains, and appointing a certain player as the face of the club is something that is done in Australia, and it works very well," explained Morrison.
"Austin has been here a long time and is a player who enjoys doing the promotional work and getting his face in the papers.
"He's very good for the club and the natural choice for this role, which I know he was delighted to accept."
Hooker or halfback Scott Spaven captained Hull KR in his Academy days, and recently went on record to express his interest in the captain's role at the Rams.
And Morrison says he was pleased to offer the former Doncaster man the opportunity to lead the team on the field.
"Scott will make decisions on game day and throughout matches. He's a good leader who has captained plenty in the past and, as a halfback, is somebody who gets his hand on the ball fairly often.
"He's been very vocal at our training sessions so far and is definitely the player who has worked the hardest to gel the new-look squad together.
"Scott was happy to take the role," Morrison added, "and I believe it will help bring the best out of him as a player."
Tickets for the Eastern Terrace Fundraising Dinner on Friday January 19 are available to purchase now by calling 01924 465489, and can also be bought before and after this Sunday's clash with Halifax (3.00pm KO) at the Tetley's Stadium.
Dewsbury rams media
Edited by Honor James, 04 January 2013 - 12:36 PM.