Castro has played in all 94 games the Cubs have played this season, and is batting .276 with 11 home runs and 52 RBI. He was voted by the players to the 2014 All-Star Game.
The Cubs do have shortstop Javier Baez, who is playing at Triple-A Iowa this season. He made his first minor league start at second base on Thursday. Chicago also acquired shortstop prospect Addison Russell from Oakland in the six-player Jeff Samardzija trade. He is currently at Double-A Tennessee.
The Cubs are 40-54 going into the second half of the season, and sit at the bottom of the NL Central. They are 12 games behind the first-place Brewers.
- Sarah Barshop