"Maybe some of that, maybe some of getting pounded in, breaking balls away, fastballs in. You know, you just try to adjust. Over the course of the season it gets to where you're struggling a little bit and they're pounding you in, so you just try to clear that front side and get them out of there a couple of times.
"Whatever the case may be, you go through so many things during the season that it could be everything. But this basically will get me to not worry about any of that. Just hit the ball back up the middle."
Hitting coach Derek Shelton noted that he thought Roberts "got a little bit big" last season.
"He got a little bit out of control with his swings," Shelton said. "It's typical when you're searching for things and you try to over-swing, especially coming to a new team and I think sitting back at home [over the winter] and the reflection of it a little bit. He came to [trying to hit the ball up the middle] and he's been outstanding with it."
Roberts went 0-for-2 with a walk in Thursday's game against the Orioles.
Bill Chastain is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.