Reba has previously hosted the prizegiving four times, but the former Hootie & The Blowfish frontman has never fronted the big show.
Rucker reveals he's studying McEntire's past shows to get a feel for the job, adding, "I've got Reba to lean on, so I'm gonna do my best and I know that if I need anything she's gonna be there for me."
Reba reveals there will be an audience at the event, unlike the recent Academy of Country Music Awards, which was staged in Nashville, Tennessee without a crowd.
"There will be people that we will get to sing to, talk to," she explains. "It will be energetic, fun; everybody's gonna get dressed up just like we always have and get to present awards to folks who have had a wonderful year, despite the COVID and everything else that's been going on."
The co-hosts aren't giving anything away about the planned performances, but Rucker admits he has always dreamed of duetting with Reba.
"I would love to do anything I can with this extremely talented woman," he tells "Good Morning America".
Miranda Lambert is leading the nominations at the 2020 CMA Awards with seven, including the coveted Entertainer of the Year and Female Vocalist of the Year. Luke Combs trails behind with six nods, also eying the Entertainer of the Year prize in addition to be named in Male Vocalist of the Year category.