Donnie was indeed willing to meet with this Mr. Walker.
A normal person visiting Atlantic City wouldn't think about meeting with so-called Atlantic City bigwigs like Donnie Block.
All they care about is whether they're having a good time in Atlantic City.
Only two kinds of people, after experiencing the splendors of Atlantic City, might want to meet someone like Donnie, a big shot of the city.
The first kind is Ponzi-schemers, who need funding from bigwigs like Donnie.
The second is someone from a family with some status, yet within such a family, they themselves do not hold much sway; unlike high-status individuals who can simply call Donnie's office and arrange a meeting.
Regardless of which type they were, they might be beneficial for Donnie.
However, just as Donnie was preparing to meet with Walker the next day, he encountered someone he didn't want to see.
Federal Agent Diesel Mallard!