After winning the world title in front of his home support, Crocker had said he would be willing to fight Conor Benn “anywhere”.
However, Benn has stepped up to middleweight to fight Chris Eubank Jr and Frampton says dropping back to welterweight “would be very difficult”.
Frampton says a compromise in weight could be made and the fight would “put Lewis’ profile into a different realm completely”.
“It would make a lot of money, but I don’t think Conor Benn is going to box at welterweight again,” Frampton said.
“But if a fight like that can be made I would say to take it with both hands. It would be a very winnable fight for Lewis and there would be plenty of dough on the line.
“You have to remember that Lewis isn’t a small welterweight, so maybe a fight could be made at light middleweight.”
Frampton says that being world champion makes arranging big fights “a little bit easier” and he hopes to see Crocker take on a unification bout in the future.
“Whatever happens in Lewis’ career, he can call himself a world champion.
“I would like to see a few defences and maybe a unification. He’s very capable of all that.
“I hope he keeps continuing to win and coming back to Belfast, that’s important.”