Underwood said in an interview with NBC Sports that she and Fisher are waiting to celebrate his birthday until after the Predators complete their run for the Stanley Cup.
"I didn't get him anything," she confessed. "I will, though. After all this is done and we have the cup, maybe that can just be his birthday party!"
Underwood did dedicate a sweet message to Fisher online. The NHL center was named captain of the Predators in September.
"Happy birthday to this handsome hunk! I'll never forget the day he told me he was asked to wear the 'C.' I was so proud on that day and I'm even more proud now to see him play in the #StanleyCupFinals," Underwood wrote. "He's definitely the only FISH in the 'C' for me!"
Underwood and Fisher married in 2010, and welcomed their first child, son Isaiah, in 2015.
The singer told "Entertainment Tonight" in April that she's leaving the possibility of baby No. 2 up to "God's good timing."
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