Stapleton said getting the pop superstar to join him onstage was as easy as picking up the phone.
"We had these nominations and thought we were gonna get, maybe, a slot to perform," he said. "So I called him up and, and asked him if he'd be interested in doing it and he was like, 'Yeah man, I'm in. Just tell me when to show up.' So here we are, we're gonna do it!"
Timberlake is a big fan of Stapleton, and has tweeted about him in the past. Apparently, Timberlake's wife Jessica Biel likes Stapleton's music too.
Stapleton said he'll be singing "Tennesee Whiskey," a cut from his CMA-nominated album Traveller, during the joint performance, but won't reveal what Timberlake will be singing.
"We'll just save it for the show," he demurred.
The singer/songwriter and former frontman of the bluegrass group The Steeldrivers is up for three awards overall: Male Vocalist of the Year, New Artist of the Year and Album of the Year.
Considering his album Traveller has yet to produce a big radio hit, that's pretty impressive, and certainly Stapleton never expected those accolades.
"You kinda make records and, and you hope for good things to happen, but you don't know what's gonna happen and, and that's part of the fun of it," he said. "But then, nothing I could've thought would've happened would be as good as what this year's been. So I'm just gonna try to enjoy the moment of it, 'cause it may never happen again. So I'm just thankful for it."