After his exciting but flawed points win over Samuel Vargas in Birmingham on Saturday, Khan seemed to prefer a clash with faded legend Manny Pacquiao, his former sparring partner.
However, the British public, as well as Brook and Hearn, much prefer a huge stadium fight which would settle a long-running war of words between the Englishmen.
“It’s down to them,” said Matchroom boss Hearn.
“It has to happen next or it will never happen, so it’s up to these guys.
“There is only so much we can do; we will listen to the public, we know Amir wants Pacquiao and he will fight Brook.
“But it’s now or never for the Kell Brook fight.
“Amir will have two weeks off then we will sit round the table. Kell wants the fight and I know Amir will fight him.”
Khan, however, seems to prefer a more internationally-appealing scrap with Pacquiao, who he trained with under Freddie Roach.
“Both fights are massive but Manny is someone I’d love to fight first. I’ve always wanted that fight,” said the 31-year-old.
“Manny and I trained together and he’s a southpaw. I’ve got a 100% record against southpaws and that would be a more technical, tactical fight.
“Let’s see what happens. At the end of the day we’re businessmen, and we do what makes financial sense.”
Khan had to climb off the canvas before comfortably beating the game, but limited, Vargas in Birmingham.
The Bolton welterweight, in his second fight since returning to the ring after a two-year absence, was knocked to the floor in the final moments of the second round.
Colombian-born Vargas had already been put down himself when he stunned Khan and the capacity crowd.
But, with Brook watching at ringside, Khan recovered and floored Vargas again before eventually running out the unanimous points winner.
The second round was only 20 seconds old when Vargas hit the canvas, sent on his way by a fearsome left jab.
He was up quickly but was immediately sent staggering backwards again amid more lightning Khan combinations.
But the elephant in the room, Khan’s fragile chin, let him down right at the end of round two as a long-range right hook left him on his backside.