No top quality opponent is going into someone else's backyard on 30 days notice.It will be a tomato can who can go a round or two at best.
No chance his team would let him fight Callum right now as he is mandatory for Abrahams title, they want to keep the title in house.
Hearn will try to get a final eliminator with the WBC I'd imagine. Zac Dunn is highly ranked, unbeaten and Australian so he'd fit the bill. Why Hearn is chasing to be WBC mandatory for Smith so soon after Jack fought Groves is beyond me. The fight won't happen until next summer at the earliest.
The only way groves would take that fight would be if it was a guaranteed shot at badou for the winner