Wahlburgers, the burger specialist founded by brothers Mark, Donnie, and Paul Wahlberg and the subject of an A&E reality show, will open this winter at the Piazza at Schmidt's in Northern Liberties.

No specific opening date has been announced.

But in the meantime, a Wahlburgers food truck will serve a limited, changing menu outside the site, in the former Darling's Diner at the Rialto at the Piazza (1033 N. Second St.), beginning Saturday, Oct. 31.

Among the items will be the one-third-pound Our Burger, Alma's Favorite Chicken, Portobello Mushroom Cap, Tater Tots, and Aqua Hydrate. (See menu.)

The truck's hours haven't been set just yet, but probably will be tied to weekends.

Local developer Artie Giordano, who plans multiple locations around here for the Massachusetts-based restaurant, is soliciting ideas for a signature "Invincible Burger," inspired by Mark Wahlberg's 2006 movie Invincible, about Eagles great Vince Papale. A contest, starting Nov. 1 on Facebook, will ask fans to help choose the toppings for the special sandwich.

Wahlburgers will serve made-to-order beef burgers with assorted toppings, beef hot dogs, salads, fries, tots, and specialty frappes. A full bar will serve draft and bottled beers (including the Wahlbrewski, a Harpoon Brewery custom unfiltered pale ale), wines by the glass, cocktails, and adult frappes.

Wahlburgers nominally will replace PYT, which closed in early October pending a 2016 opening near the Fillmore as the Piazza's burger restaurant-slash-bar.