"I hit a little rough patch," Hart said. "I couldn't get righties to ground out anymore, and I couldn't get them off my changeup, and I was wanting to all year to be able to throw a backdoor slider. So I called him [O'Day], talked to him and asked him about when he throws it, what kind of hitters he throws it to, and when the best time to throw it is. We had a conversation while he was driving up here to the ballpark, and I think it was maybe but two weeks later that I was up here as his teammate. It's great."