Javier Baez has started the last five games at shortstop for Castro, and was expected to move back to second base. Infielder Logan Watkins was optioned to Triple-A Iowa to make room on the roster for Castro.
Baez went 3-for-22 with two home runs on the just completed six-game homestand and surprised Cubs manager Rick Renteria with a bunt attempt with one on and no outs in the sixth inning Sunday.
"He's not your prototypical No. 2 type hitter," Renteria said of Baez. "Would I rather have him swing the bat? Of course. But I will say this, he's thinking about the game. Everybody talks about young players not thinking about the game, and he was thinking about doing something productive for his team, [but] not necessarily something I would want him to do in that moment. We talked to him. His mind was in baseball mode. Sure, I would want him to swing the bat."
Baez and Watkins were two of five rookies in the Cubs' starting lineup Sunday, the first time the team has had that many since Oct. 3, 2012, against the Astros at Wrigley Field. The last time the Cubs started five rookies before rosters expanded on Sept. 1 in a game was in the second game of a doubleheader, Aug. 18, 2012, against the Reds (Steve Clevenger, Anthony Rizzo, Adrian Cardenas, Brett Jackson, Brooks Raley).
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings, and you can follow her on Twitter @CarrieMuskat. This story was not subject to the approval of Major League Baseball or its clubs.