"The work [Castro] put in on his defense with the new coaching staff was a big part of what made us feel comfortable extending him for as long as we did," said Cubs general manager Jed Hoyer, who announced Castro's seven-year, $60 million contract extension on Tuesday. "He did have to put work in and make adjustments, and he did that."
Castro does lead all Major League shortstops in errors with 21, but Sveum said there's been significant improvement on how he's handled routine plays and how he's improved the accuracy of his throws.
The next step is to work on improving his pitch selection and patience at the plate. Since Castro has been slotted in the fifth spot in the lineup, Sveum said the shortstop was batting about .400 with runners in scoring position.
"He's taken to that role and had more concentration in that role," Sveum said.
Now that the deal is done, the focus for the final stretch is strictly baseball.
"It'll be interesting to see if there's any change now that this thing is behind him," Sveum said. "Hopefully, it does relax him. Being a young kid and knowing there's a lot of money and years coming his way as a Chicago Cub, I don't care who you are, 22, and knowing all of this has been going on, it has to have been a little bit of a burden."