The New Miami Subs Grill has already undergone one major change in its 26-year history, having been rebranded from its former Miami Subs moniker after a new ownership group took over the company in 2007.

Now the chain is rolling out more premium extension brands, Miami Grill and Oh! Miami Grill (OMG), following in the footsteps of other limited-service companies that are updating their concept to appeal to younger consumers.

“Our patrons are becoming younger and hipper and really want that atmosphere. We are looking for a younger age group, in addition to our core 35–65-year-old age group,” says Richard Chwatt, CEO. “You can’t sit still. It’s unreasonable to think that you are going to rely on your 26-year customer; you have to keep up with the times and become current.”

The company’s rebranding efforts, both to The New Miami Subs Grill and now to the new Miami Grill and OMG extensions, have been done to reflect “who and what we are all about. We are not just a sandwich chain,” Chwatt says.

Miami Grill will feature 2,000–3,000-square-feet fast-casual restaurants, which will serve both items already on The New Miami Subs Grill menu as well as new items. Beer and wine, as well as breakfast, have been added. The first Miami Grill opens in Cutler Bay, Florida, in June, followed by a restaurant in Waipahu, Hawaii, in July. New franchisees can operate either Miami Grill or The New Miami Subs Grill units, which include 40 franchised operating restaurants, plus seven under construction in the U.S.

Meanwhile, the OMG concept has a much larger footprint than a typical fast-casual eatery, at 6,000–7,000 square feet, with a nightclub-type atmosphere, Chwatt says. “It will be in larger spaces such as resorts and airports, and will feature a full bar and grill for that nightclub-style atmosphere,” he says.

Despite its larger footprint and bar-type atmosphere, OMG will still operate as a fast-casual concept, and not as a casual or full-service dining chain. The company has not announced when the first OMG unit will open.

The New Miami Subs Grill partnered with popular musician Armando Christian Pérez, also known as Pitbull, in 2012 to advise on the brand’s updates. A recording artist and entrepreneur, Pitbull sits on the company’s board and owns an equity stake in the company. “The collaboration of Pitbull and The New Miami Subs Grill is about two Miami brands coming together and enhancing the customer experience by connecting great music with great food in a great atmosphere,” Pitbull said in a statement. Pitbull’s music will be featured in the company’s OMG restaurants.

In a further push to appeal to Millennials, even The New Miami Subs Grill branding has been updated. While the restaurant’s interior and exterior design still reflect a Miami South Beach theme, the appearance is more sleek and modern. “The old look was a tired brand. Our renovations and rebranding, along with Pitbull’s involvement and feedback and the type of audience he appeals to—we needed that,” Chwatt says.

Younger customers are seeking bistro-style, tapas menus that both Miami Grill and OMG provide, Chwatt says. The diverse menu of Miami Grill includes wings, steak, gyros, grilled fish and chicken entrées, meatballs, Angus steak burgers, salads, and other dishes.

While the brand is keeping entrées that feature “Florida flavors,” Chwatt says, it has added other options, such as grilled or blackened fish instead of just fried fish. Menus for each of the brand’s new U.S. and international locations will also be tailored to the region in which they operate. The New Miami Subs Grill is also creating a heart-healthy menu that will be included with its standard menus.

While the fast-casual business is booming—even quick-serve restaurants are getting into the game, as Taco Bell just did with its U.S. Taco Co. brand—Chwatt believes The New Miami Subs Grill’s positioning is different than any other fast-casual chain.

“I don’t know anyone preparing fresh food and baking daily that is carrying our diverse menu,” he says. “You look at the market caps of brands like Chipotle and Panera, [and] they are a one-, two-, or three-item restaurant. That is not who we are. I don’t think there is anybody who competes in the space.”

While The New Miami Subs Grill executives are focusing on growing the Miami Grill and OMG concepts, at least one industry observer says the concept may have some work to do to convince customers that it’s a fast-casual-type experience. Aaron Allen, owner of global restaurant consulting firm Aaron Allen & Associates, says the concept’s menu items, like Grilled Tilapia Salad, do not necessarily reflect where the fast-casual industry is going.

“It’s an instance where they are trying to do cheap, and fast casual is not about cheap [ingredients],” Allen says. “Fast-casual brands have more of a point of view, and they tout their views. … The value [proposition] for fast casual is beliefs, not necessarily discounts.”