Extra bases

Mike Olt, making his third start at third base Sunday for the Cubs on Sunday, made two errors in one inning. Manager Rick Renteria wasn't concerned.

"I think he's just a little rusty out there," Renteria said. "He's been swinging the bat pretty much all spring. We'll just keep putting him out there and letting him work through it and get comfortable."

The Cubs are still deciding who will get regular time at third base this season. Between Olt, Luis Valbuena and Donnie Murphy, who will start Opening Day?

"I'm not willing to tell you, and we'll let it keep playing itself out," Renteria said.

• Left-handed pitcher Tsuyoshi Wada, who was granted his unconditional release by the Cubs on Sunday, signed a Minor League contract to return to the organization on Monday.

Wada gave up seven runs on 10 hits over 5 2/3 innings in three games, including one start, and will start Tuesday against the Angels at Cubs Park, one of the team's split-squad games.

"He has to continue to improve," Renteria said of the lefty. "His command was a little bit erratic during the course of the spring. He wants to continue to make strides, he wants to continue to pitch and do those things that will help him be effective."

Chang-Yong Lim is headed to Korea. The Cubs sold the contract of the right-handed pitcher to the Samsung team for cash considerations.

• Cubs shortstop Starlin Castro will host a one-day Baseball ProCamp presented by SunnyD On July 22 from 9 a.m.-12:30 p.m. CT at Evanston (Ill.) Township High School. Participants will learn fundamental baseball skills and have the opportunity to meet and interact with Castro. Each camper will receive an autographed item from Castro, and a team photo.

Castro will be joined by a prep and college coaches from the area. The camp is open to boys and girls of all skill levels from grades 1 to 8. Cost is $99. Registration and more information are available by visiting StarlinCastroCamp.com.

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.