Barton got off to a hot start in his first Major League season, batting .333 with a .409 on-base percentage and a .462 slugging percentage in April. He's just 5-for-33 in May, though, as limited playing time has taken its toll on his approach. It's the first time in Barton's career that he's been a part-time player.
"Gradually, it was coming," Barton said. "I felt it. But it's one of those things where you've got to get it before it gets you. At the beginning of the season, it was easier, coming from Spring Training, playing every day. I was still kind of in a groove. Not being used to it, I never had to really adjust to it."
One area where Barton's slump really showed was in pinch-hitting. He rapped base hits in four of his first nine pinch-hit at-bats, then went into a 1-for-8 slide. Barton picked up a pinch-hit in Wednesday's series finale against the Padres, though.
"My last at-bat to get that base hit, it took a little pressure off me mentally," Barton said. "The game before, that was probably the first game all year when I went home feeling [terrible]. I normally don't really get down on myself. ... But I felt overall that I had no plan, and that was the first time that I felt lost."
Barton is caught in a tough situation. He's the fifth outfielder in a five-man rotation, and each of the other four players has been at least fairly productive.
So while he would like to get at-bats in order to get back on track, he must get back on track in order to earn those at-bats.
"He's a little in between at times," manager Tony La Russa said. "He's taking pitches. Most of the time, when he was taking pitches, they were balls. And usually when he swung, he swung at strikes. Now he's swinging at balls that aren't strikes. So he's a little bit in between."
Matthew Leach is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.