"I think everybody sits there hoping one day he'll come back and put himself back in the mix in New Zealand, and we get the benefit of all the experience he's had at an international level and obviously quite a few years successfully at club level as well.
"From Ireland's point of view, you want to try and lock him [Schmidt] in and from New Zealand's point of view, if Steve doesn't continue, they're going to want all the options on the table.
"It will be hard for Joe, because he wants to concentrate on doing a good job for the next 12 months, but if he wants to put his name in the hat, it will be pretty good to have a coach like that looking around."
The New Zealand-born Schmidt has been plying his trade in the Northern Hemisphere since 2007 when he left his post as Blues assistant coach to take up an offer with Clermont in France.
Since taking over the reins of the Irish national since in 2013, Schmidt has helped lift the nation from ninth ranked to second, and last season led them to their third Six Nations Grand Slam, which they previously achieved in 1948 and 2009.
However, should Hansen choose to step away from his post after next year's World Cup and Schmidt not throw his name in the ring, McCaw also listed Crusaders coach Scott Robertson, Hurricanes coach John Plumtree and Japan coach Jamie Joseph a possible candidates.