"It's BIG. Me and bud @ZacEfron been talkin' bout this one for a long time. And someone get my baby oil. #RatedR," Johnson tweeted.
Added Efron: "So stoked brother - baby oil for 2 plz."
Johnson first confirmed last year that the movie was in the works.
"Edgy, raunchy and hopefully, funny as all hell. Cue slo mo running on the beach... #WhoNeedsMouthToMouth #RedShortsBeHugginABrotha," he wrote.