Lambert and Shelton are both nominated for Video of the Year. Lambert is nominated for "Only Prettier" and "The House That Built Me." Shelton is nominated for "Hillbilly Bone," with Trace Adkins.
Will there be tension between the pair?
Lambert said on "The Early Show" Tuesday, "Probably. There's always a little friendly competition between us -- sometimes not-so-friendly. But yeah, I'm really proud of him and he's well-deserving of the nominations. He's a great vocalist. He deserves to be in that category, definitely."
"Early Show" co-anchor Erica Hill said, "A little healthy competition to keep the relationship going."
Lambert replied, "Absolutely."
Lambert is this year's top solo Academy of Country Music Award nominee. She's up for seven ACM Awards, including Entertainer of the Year, Top Female Vocalist of the Year, Single Record of the Year for "The House That Built Me," Song of the Year for "The House That Built Me," Video of the Year for "Only Prettier" and Video of the Year for "The House That Built Me" and Vocal Event of the Year for "Coal Miner's Daughter" with Loretta Lynn and Sheryl Crow.
Of her nominations and her year of success, Lambert said, "Just all of 2010 and, so far, 2011, have been really great - just one of those years where you can really feel a push in your career and in your life, just changes and all the hard work paying off. And it's been a really, really record-breaking year for me just personally and professionally. I'm so thankful."
Her fiancee, Shelton, will co-host the ACM Awards with Reba McEntire.
Ronnie Dunn, who is now flying solo after the break-up of super group Brooks & Dunn, also announced the award nominees live on "The Early Show."
Dunn, as part of Brooks & Dunn, has won a total of 27 ACM awards -- more than any other artist or group. He wasn't nominated this year. He'll be performing "Bleed Red," his first single for the first time on the awards broadcast.
What's the change been like for the country star and his former partner? Dunn said it was "welcome for both of us."
He said, "I think the other guy will tell you the same. (I've) been hiding out in the studio for the last few months and really digging it, enjoying it. Having a great time."
The ACM Awards are broadcast live from Las Vegas on Sunday April 3, 2011 at 8 p.m. on CBS.