"So now the owners have a decision to make and we will continue to talk more about that this week."
They have been contacted by senior northern jockeys while multiple premiership winner Lisa Allpress rode Wolverine to victory three starts ago and remains very much in the mix, with Bergerson suggesting she has one key factor in her favour.
"She (Wolverine) is a funny filly and doesn't really seem to like men much," he added.
The question of who rides Wolverine may have been answered by now had the borders been open, with the filly having been purchased for future racing by syndicator Australian Bloodstock, who would have undoubtedly wanted a leading Australian-based rider, like James McDonald, if there were no travel restrictions.
The unavailability of Australian riders, the injury to Johnson and recent overseas departure of Samantha Collett is going to make for some rare alliances come Karaka Million night.
The Jamie Richards and Te Akau stable that have won the last five Karaka Millions could have five, six or even seven in the 1200m dash for cash, although the two juvenile winners they had at Te Aroha on Monday, Kabugee and Maven Belle, won't further confuse that picture as both are ineligible.
Te Akau's retained jockey Opie Bosson who will clearly ride what is deemed to be the stable's best chance and, with his weight under control, he has the option of that being a filly because he rode at 54.5kgs on Saturday.
Bosson has no firm opinion on his potential mount, with the Ellerslie meeting this Sunday a possible pointer as Richards has used the two-year-old race at this meeting successfully as a Karaka Million lead-up before.
Whoever Bosson ends up on will be a market mover for sure but then Richards will have some juggling to do to fill his other saddles, providing all his juveniles remain sound and happy as the firmer summer tracks start to test shins and joints.
The stable also has On The Bubbles as the $2.20 favourite for the $1million Karaka Classic at the January 22 twilight meeting, with Bosson certain to ride him.
Te Akau have confirmed their talented filly Bright Blue Sky, who was a brave fourth in her Australian debut at Doomben on Boxing Day, will take her place in the Magic Millions two-year-old on the Gold Coast on January 15 should she make the final field.