What's not to like about Theriot? He is batting .533, best in the majors this spring.
His average actually fell slightly Saturday after he went 1 for 2 with a three-run double in Chicago's 4-0 victory over the Kansas City Royals in a matchup of split squads.
Asked for a theory about Theriot's hitting, Piniella mentioned the player's work with new hitting coach Rudy Jaramillo. Piniella also said: "Maybe having Castro around had something to do with it, too. You've got a nice young player pushing you."
Theriot, entering his fourth season as the starting shortstop and his first as the leadoff hitter, has been reluctant to discuss the teenage phenom who was trying to take his job.
While acknowledging recently that "competition brings out the best in all of us," Theriot said "it takes a little bit more than just ability" to handle big league expectations.
Castro handled those expectations superbly, batting .423 before he was sent to minor league camp after Saturday's game. The Cubs want him to play everyday at Triple-A Iowa rather than be a backup in the majors.
"Castro just had a phenomenal spring," Piniella said. "Nineteen years old, to come in here and look like a veteran and do the things he did ... he came in here highly touted and he left here even more touted, as far as I'm concerned."
On the mound, meanwhile, Carlos Zambrano displayed the form that once made him the Cubs' most highly touted pitcher.
The $91.5 million right-hander, who reported to camp in excellent shape after winning only nine times last season, allowed three hits, walked two and struck out four in five innings. He has given up one run in nine innings after yielding five on March 10.
He's tired of talking about 2009 -- both when it comes to his disappointing season and that of the Cubs, who fell to second place after winning two straight division titles.
"We don't care about last year, man, it's already in the past," Zambrano said. "I'm happy the way spring training is going. Not only me, but everybody is taking care of business."
Edgar Osuna, a 22-year-old left-hander trying to be Kansas City's No. 5 starter, pitched three innings and allowed all four Chicago runs in the second.
"I can't worry about whether I [make the rotation] or not. I'm just trying to do my job," he said. "I need to be more consistent and not fall behind in the count, like I did in the second inning. I've already learned a lot and I have a lot more to work on."
After scoring 38 runs in their previous two games, the Royals were blanked in both split-squad games Saturday. They also lost 1-0 to Milwaukee.
The Cubs sent down OF Brad Snyder along with Castro. ... Royals CF Rick Ankiel (sore right ankle) is scheduled to play DH in a minor league game Sunday. If all goes well, he'll return to the lineup Monday or Tuesday. ... RHP Justin Berg and IF Darwin Barney were co-champions of the Cubs' version of American Idol. Chosen from among seven rookie finalists, guitarist Berg performed a song he wrote five years ago while in the Yankees' system and pianist Barney did a Coldplay song. Each won $10,000 for his favorite charity. Four Cubs veterans, as well as Hall of Fame quarterback Steve Young, served as judges. ... Cubs 3B Aramis Ramirez (sore right triceps) went 1 for 5 in a minor league game. He said he feels fine at the plate but isn't ready to throw just yet.