"Dick Clark's New Year's Rockin' Eve with Ryan Seacrest" airs on ABC Friday night, but on Wednesday, two of the stars scheduled to perform in New York's Times Square -- LL Cool J and Chloe -- pulled out, due to a positive COVID test.

Host Ryan Seacrest, however, said the show must go on.

"In our minds, the show is always going to happen. There's always going to be a ball that drops, whether there are people there or not. I think we learned that last year!" he told ABC Audio. "Over the years, there have been situations where we thought ... a performer couldn't make it in or they weren't going to be able to get there to perform. So we are trained to know how to react to last-minute changes."

"We're going to pivot -- we're going to put Journey " -- another previously announced Times Square performer -- "in [LL Cool J's] spot," he added. "We have enough performers and enough different moving parts that the show will always fill any gap."

This year marks the show's 50th anniversary, and first-time co-host Liza Koshy said the show will "commend the incredibleness that Dick Clark began."

"There are so many clips that we have that we're playing back from the '80s, '90s, 2000s ... it's been an incredible journey," she said. And with additional performances in L.A., Puerto Rico and New Orleans, Koshy said, "People are going to be tuning in to just layers of performance and entertainment the whole night!"

The fun begins at 8 p.m. ET, airing live on ABC. Co-hosts in cities other the Big Apple are Billy Porter, Ciara and Roselyn Sanchez, who will oversee the show’s first-ever Spanish language countdown from San Juan. Performers include Måneskin, Avril Lavigne, AJR, Travis Barker, Polo G, Walker Hayes, Daddy Yankee and OneRepublic.

As for why New Year's Rockin' Eve is still rockin' 50 years later, Seacrest reflected, "There's a mixture of nostalgia and relevance ... [It's] a part of our DNA!"