No Frost, just ice

UNDERSTUDIES took over “MJ: The Musical” on Saturday — and fans weren’t happy with their moonwalking. After forking over $200 apiece for tickets, a source told us, “It was so disappointing for the cast to be out . . . having that many understudies did not produce an excellent show!” Eight members of the cast were absent — including the lead role of Michael Jackson as played by Myles Frost (above). His stand-in, Aramie Payton, has been performing as the King of Pop since Jan. 13 while Frost is on vacation. But the other stars of the show are seemingly fighting winter bugs, including COVID-19. The rep confirmed that “there were a number of cases at ‘MJ’ recently,” but said it didn’t stop the cast from putting forth its best effort.