Extra bases

• Left-hander Felix Doubront threw a side session on Saturday, his third since joining the Cubs, but there was no word yet regarding a possible Minor League rehab outing for the left-hander. The Cubs acquired Doubront on July 30 from the Red Sox for a player to be named, and he is on the disabled list with a left calf strain.

• Renteria said he's happy with Arismendy Alcantara's play so far in center field. Alcantara has primarily been a second baseman, and switched to the outfield this year at Triple-A Iowa. So far, Alcantara's reaction time and ability to read the ball off the bat have been good.

"Over time, his angles will continue to clean up, his approach and understanding of situations and when to get the ball in a little stronger, and when to hold up more -- all of that will continue to develop," Renteria said.

• Jorge Soler, ranked No. 6 on MLB.com's Top 20 Cubs Prospects List, hit his fifth home run and an RBI double on Friday for Triple-A Iowa. He is batting .313 in 16 games, and could join the big league team in September when rosters expand. Soler is already on the Cubs' 40-man roster.

• The Cubs won't be adding Cole Hamels to the rotation this month. The 48-hour deadline passed for the Cubs and Phillies to work out a deal after the Cubs claimed the left-hander off revocable waivers. The Phillies, who most likely were looking at some of the Cubs' top prospects in exchange, have pulled Hamels back.

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.