Last season, Barney, 24, batted .317 at Double-A Tennessee and then hit .264 at Triple-A Iowa. He was the Smokies' leadoff man, batting .382 in the No. 1 spot.
The discussion on who will back up Ryan Theriot on the big league team started when Andres Blanco sprained his right knee Saturday. He will be sidelined 10-14 days.
"If we needed a backup infielder," Lou Piniella said, "it would be more Barney than it would be Castro. The organization wants Castro playing [every day] and rightfully so. That's what's good for him and good for the Cubs."
Barney has been the forgotten shortstop.
"You kind of expect that when a guy like Starlin, who has the hype and has the talent that he does, he's going to come in and get a lot of innings," Barney said Monday. "My job is to go out there and go about my business and try to get better every day.
"[Castro's] a good dude," Barney said. "We chat here and there. There's no animosity between us. Things are going to fall into place."
That's the perfect attitude for all of the Cubs' Minor League players to have. Somehow, these things have a way of working themselves out.
"If the Cubs need me and they call me at a certain time, I'll be ready," Barney said. "If Castro is the guy who will play that position, then that's what will happen. All I can do is focus on my own game and what I'm doing and what I can possibly do to help this team. Whether it's this year or next year, who knows?"
He's not losing sleep over playing time. Last spring, Barney got a lot of playing time with the big league club in Cactus League games.
"They had to see me and see what I could provide and what I brought to the table, and I think that's what they're doing with Starlin this year and rightfully so," Barney said. "The guy is talented and he's a nice kid. He's poised for his age. Where things are going to fall into place, I don't know.
Barney also knows Blanco has the edge in the battle for backup infielder on the Opening Day roster.
"There's no doubt in my mind that Andres Blanco gets the job defensively and can be a backup guy at any point," Barney said. "If they're looking for a backup guy, they already have a good one. A little twist of the knee is not going to lose his spot."
Castro and Barney were working in the same group during infield drills at Fitch Park before the Cubs moved to HoHoKam. Barney isn't scouting his competition.
"I'm not working out next to a guy and saying, 'Oh, am I better than him?'" Barney said. "It's what kind of guy is he? Is he personable, nice, respectful? I've seen that in him."
Castro is getting a little more comfortable with his English, but the Cubs may want to move his locker. Right now, he's next to Kosuke Fukudome. Asked if he can speak any Japanese, Castro laughed.
"No," he said.
"We have a lot of talent up the middle," Barney said. "I think the Cubs are happy about how much depth they have. There's no doubt in my mind that for a backup role, they already have the guy. They like Blanco and so do I. He's a great dude. In the long run, is Castro their guy? Probably. You don't know. There's still a lot of baseball to be played."
If Barney is being overlooked, imagine how Ryan Theriot feels. It's still his job.
"How can you say somebody is going to take the job of Ryan Theriot?" Barney said. "He's such an established player, poised, and does what the Cubs need him to do. People are always looking for the next superstar and there's possibilities in everybody."
Carrie Muskat is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.