Garth Brooks is one of the most seasoned performers of all time, but even he knows his limits. The singer is scheduled to perform at the 2015 ACM Awards, just days after a series of shows in Portland, Ore., as part of his ongoing World Tour, and he says that it might be more than his voice can handle.

"I saw an ad on the television the other day, and they nailed it right on the head," Brooks tells SiriusXM's Storme Warren. "It's a once-in-a-lifetime performance. I'm afraid I'm going to break down and cry right in the middle of it because it's so emotional.

"But also, you've got to remember, this is after five nights in Portland," he continues. "After the first show [in Portland], I won't have a voice left. So we actually went in, and we taped -- just in case we have to lip sync -- we taped a performance that was solely made for the awards show.

"So we don't know if we're lip syncing yet or not," Brooks concludes. "But my bet is, if I know Portland, we're not going to get out of here with anything, and then you've got to fly down and do that show. So we'll see."

Brooks is also nominated for Entertainer of the Year at this year's ACMs, which marks his first ACM nomination in a regular category since 2001.

“When they were giving out nominations for the ACMs, this tour was two or three months old. That’s a sweet nod,” Brooks says. “So whether you win or not, it’s like, can’t believe you’re in it, so it feels cool.”

For the Oklahoma native, it's only fitting that his return occurs during the ACM Awards' 50th anniversary celebration.

"I'm excited and looking forward to performing at it," Brooks adds. "This is Cowboys Stadium. This is big time."

Brooks and his wife Trisha Yearwood will be co-hosting an ACM Lifting Lives fundraising gala on Saturday (April 18) as well, and the singer-songwriter will also receive a 50th Anniversary Milestone Award during the ceremony.

The 2015 ACM Awards will air live from AT&T Stadium in Arlington, Texas, on April 19 at 8PM ET on CBS.

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