In an interview with a US TV show, he said the star sounds "tired" because she's been working on the performance.
He also said he was "shocked" to hear her pregnancy news and only found out after she made the announcement on Instagram.
But he said he'd since had a "wonderful daughter-dad conversation" with her.
Beyonce's nominated for nine Grammys at this month's awards.
She's up for album of the year with Lemonade against Adele's 25. They're both nominated for record and song of the year too.
Her pregnancy announcement is now the most popular Instagram post of all time, with more than nine million likes.
She's also released more photos from the shoot, including ones of her under water, lying on a bed of roses and sitting on an old car.
Alongside the original picture of her bump, she wrote: "We would like to share our love and happiness.
"We have been blessed two times over. We are incredibly grateful that our family will be growing by two, and we thank you for your well wishes."
After working as his daughter's manager, Mathew Knowles also called the pregnancy announcement "smart".
"I think it was a strategy. I think there's more to come," he said.
Adele, Bruno Mars, the Weeknd, Daft Punk and Alicia Keys are already confirmed to perform at the Grammys ceremony in LA on 12 February.