So this was something different on Saturday when he relieved James Shields in the sixth inning during a 7-1 loss to the Twins. But Duffy reeled through all seven batters he faced, struck out three and used 45 pitches to do it.
"It was nice to get back out there and be a part of the team again. Shields did a great job of damage control. He pitched a heck of a game and we were fortunate enough to save the 'pen for tomorrow," Duffy said.
"That's what he does. For a good starter, I think how good you are is dictated by how good you are on your bad days. He had great stuff today. They were spittin' on a lot of great pitches and he just persevered and got through 5 2/3, and did a great job of preserving the 'pen."
Shields did retire 11 of the 13 batters he faced after the second inning. So the rest of the bullpen rested and manager Ned Yost was pleased with that development.
"It was real important, especially after the fact that he threw 50 pitches in the second inning," Yost said. "That's a huge workload for one inning. When you've got your ace on the mound, it starts to give you a little bit of concern, making sure he doesn't overdo it.
"But the thing about James Shields, what makes him so great, is that he never stops competing -- ever. It doesn't matter what the situation is, he continues to compete. He was bound and determined to throw every pitch that he had in his tank today to get us as far as he could to save that bullpen."
Yost saw Duffy's showing as an example of what he might do in a much tighter game.
"That was an encouraging sign today. Again, we're not firing on all cylinders offensively, which I knew we can and I know we will," Yost said.
"But there are still going to be times when you're going to need to protect the one-run lead from the sixth inning on and the more power arms you have down there in the bullpen, the easier it's going to make it to do that. So, we think Danny is going to fill that spot nicely -- to have another power arm that we can add to our arsenal down there."