This season he's batting .313 overall, .341 with runners on and .316 with runners in scoring position, but he's been striking out more, with 31 Ks in 44 games. Last season he struck out 25 times in 52 games in April and May.
"It's time," Sveum said on Friday. "[We haven't been] scoring throughout the whole season, and Mather's been as good as anybody swinging the bat, so I'm going to give him a little opportunity to see what he can do.
"Like I told Castro, 'It's not a demotion, it's more shaking the team up.' He was great about it -- he was like, 'Hey, I just want to win, I don't care where I hit in the lineup.' He took it well and completely understood."
Mather started in center field -- he's also played third base and left field.
"I'm going to give him an opportunity to see if he can spark us and drive the ball," Sveum said. "He's really carried over from Spring Training, and it's an opportunity for him. The limited time he's played off the bench, he's swung the bat well, and I think he's got nine walks off the bench. He's always been a real good outfielder."
The Cubs would like to see a little more pop out of the No. 3 spot in the lineup. Castro has hit two home runs; only the Phillies have had fewer from that spot (one).
"[Castro] is hitting .350 with men in scoring position, he's hitting over .300," Sveum said. "[That's] pretty good out of the third spot. You might want more home runs and quick runs that way. You take some of those balls he hit with the wind howling in [at Wrigley Field], he could have five or six home runs.
"There's nothing he's done to be put down in the two-spot. It's more change to get everything going. You never know. Sometimes you pick a lineup out of a hat and you win. I wasn't going to go that far. You can do that in the American League, not the National League."
Was he close to randomly picking a lineup?
"Not too far," he said, smiling. "You never know."