After lasting a total of 2.1 innings in his last two starts, Larry Rothschild, the Cubs pitching coach, pulled Silva aside.
Rothschild said he wanted Silva to start using his lower half more and get on top of the ball.
The result: five innings of one-run ball and his staff-leading 10th win against the Astros on Monday.
"My key is to keep the ball down," Silva said. "I'm a sinker-ball pitcher and a change-up guy. That's the main thing I need to focus on, just keep the ball down and hit my spot."
Rothschild's ability to immediately address flaws makes him one of the most valuable coaches in baseball.