Extra bases

• The Cubs may make a roster move Friday when they open a three-game Interleague series against the Astros, manager Dale Sveum said. The team is currently carrying eight relievers. One option would be to activate catcher Steve Clevenger from the disabled list. He's been sidelined since April 14 because of a left oblique strain and was currently rehabbing with Triple-A Iowa.

• There is no timetable for David DeJesus' return, but the outfielder will most likely be out at least one month after spraining his right shoulder in a collision last Friday at Citi Field.

"It's one of those injuries, from the time it happened a few days ago, it's definitely a month before he's back on the field," Sveum said.

Luis Valbuena has done well subbing as the leadoff man for DeJesus.

"[Valbuena] is a guy who has always been able to take his walks and see some pitches and drive the ball and do some things," Sveum said. "So far, it's really, really good."

• Seventh-round Draft pick David Garner, a right-handed pitcher who starred at Michigan State, has apparently signed with the Cubs. Garner's signing was announced by two other Cubs picks who have already signed. Trey Masek, a fifth-round selection, tweeted: "Congrats to my roommate @DG_token16 on signing today! #Cubs." Second-round pick Rob Zastryzny also tweeted: "Got another #Cubs player sign today! Congrats @DG_token16 on making it official."