Pitcher Carlos Silva was released from Northwestern Memorial Hospital on Monday after undergoing what the Cubs said was a successful cardiac ablation.
The two-hour procedure, called radio frequency catheter ablation, was performed by Dr. Bradley Knight and was done to regulate an irregular heartbeat.
Silva left his Aug. 1 start at Colorado because of a rapid heartbeat.
The Cubs say they expect Silva to begin light activity this week. He could begin a throwing program next week. The Cubs said they expected Silva to pitch again this year.
Lee takes leave: First baseman Derrek Lee was not at AT&T Park on Monday for the series opener against the Giants. He was driving to Sacramento to be with his grandfather, who is ill. Cubs manager Lou Piniella is in Florida, tending to his ill mother.
Roster move: The Cubs recalled right-handed pitcher Marcos Mateo from Class AAA Iowa and sent pitcher Mitch Atkins to that club. Mateo, 26, is looking to make his major-league debut. He would be the 11th rookie pitcher to see action for the Cubs this year.
Jo-dee, Jo-dee: Former Cubs catcher Jody Davis has been suspended six games by the Northwest League. Davis is the manager of the Cubs' Class A Boise affiliate.
On Saturday at Everett (Wash.), he pulled his team off the field after a lengthy rain delay, and the action resulted in a forfeit.
"Jody made a decision that the playing field wasn't conducive to playing, that our players should not have been on that field," farm director Oneri Fleita said. "If that's what he believes, I'm fully supportive."