Ian Kennedy wants opponents to know he's trouble, and is letting Taylor Swift tell them

Baseball players put a lot of thought into their walk-up songs.

What gets me pumped? What will make the crowd go wild? What will strike fear in the heart of my opponent?

But D-backs ace Ian Kennedy didn't use any of these criteria. In fact, he left his decision up to an 11-year-old girl --  Kylie Hall, daughter of D-backs President and CEO Derrick Hall. And that's why his walk-up song is "I Knew You Were Trouble" by Taylor Swift.

"It pumps me up because the chorus is really cool," Kylie said. "So I thought it would be cool to walk up to because it would get him excited, too." 

Kennedy likes the song. And after earning a win in his Opening Day outing on Monday, he says it's working so far. 

As for whether T. Swift will strike fear in the hearts of NL West rivals, I guess we'll find out.

-- Amber Harding / MLB.com Real-Time Correspondent