The Crows experimented playing with 21 players and a substitute at different stages of the pre-season competition.
Opinion on what type of player makes for a good substitute is divided.
Several coaches have floated the idea of handing the green vest to a back-up ruckman, while others are adamant the sub must be a running player who can help with the increased physical demands created by having one fewer player on the interchange bench.
Craig leaned towards the latter option, saying the key to a good substitute player was versatility.
"An Andy Otten or Scott Stevens would make the perfect sub," he said on Tuesday.
"Andy could come on and play down back or in the midfield … and Scott Stevens can go forward or back, so he also gives us some flexibility.
"I'm not saying that's necessarily what we'll do, but I think they're the type of players that would made a good substitute."
Craig also floated the idea of using the substitute role as part of a club's list management.
The Crows eased a number of underdone players including Richard Tambling, David Mackay and Bernie Vince into the pre-season competition by playing them as substitutes.
Craig said the substitute could be used as a way of limiting a battle-weary player's game time in the later rounds of the season.
"You might have a player that's played 15 games and playing half a game as a sub [instead of missing a game] might be perfect for him," Craig said.
"And you might do that for two or three weeks. It gives the player a bit of a rest, but you've still got some quality there [on the bench]."
The Crows will train on Tuesday night ahead of their opening-round clash with Hawthorn at AAMI Stadium on Saturday night.
Forward Ricky Henderson is nursing several sore spots and will be given until later in the week to prove his fitness.
Hawks skipper Luke Hodge is also in doubt for the game as he continues his recovery from an achilles complaint.
Andy Otten is a $142,400 defender in the Toyota AFL Dream Team competition
