Matt Barnes spent a good chunk of Monday's pregame trying to figure it all out. First was the bullpen session with pitching coach Carl Willis and bullpen coach Dana LaVangie, and then came some flat-ground work in Fenway Park's right field.

"I was just trying to get out there and get back to how it felt good," Barnes said. "The previous homestand and even in Tampa, I felt really good. Really sharp. So just trying to get back to that."

But this riddle was more than just attempting to bounce back from a bad outing. This has become a next-level mystery with a brand new set of clues.

Barnes is experiencing dramatic difference in performance when it comes to pitching at Fenway Park and performing on the road. In 27 home appearances, he has a 1.55 ERA and .176 batting average against, striking out 38 and walking just eight. But away from Fenway, the righty's numbers take a dramatic turn, with the ERA in his 28 road outings ballooning to 5.20 with 18 walks.

The latest hiccup came Sunday night at Yankee Stadium when he gave up a pair of walks and a hit before allowing the go-ahead run via Todd Frazier's sacrifice fly.

"I don't know. I honestly don't know," said Barnes regarding the reason for his splits. "If I could tell you I would be able to fix it. Maybe it's a comfort thing. Maybe it's being so used to this mound because you're throwing on it so much more. I don't know. It's always been reversed. I'm my own worse enemy."

Not only is Barnes at a loss when it comes to fixing the problem, but he also has had another obstacle thrown into the equation. Since he changed his delivery, going to a strict slide-step intead of the big leg kick the reliever previously possessed, adjustments haven't come easy.

"The hard part for me right now is having to switched to that slide step," he said. "Learning what the triggers are to make that as consistent as possible, I'm still trying to tinker with and trying to figure out. I'm like, 'OK, if I'm rushing, this is my trigger to stop doing that.' That's part of what this is. It's me trying to figure out what I can tell myself when I'm out there in the game.

"I could have told you what it was like with the leg kick. But going with this new delivery it's still that kind of process what the trigger is for me to make that adjustment."

Barnes entered Monday with a 3.34 ERA, having allowed runs in just three of his home appearances. He has pitched in the eighth inning more than any other frame, appearing there 36 times compared to his 19 outings in the seventh.