Cubs hitting coach James Rowson was out early Saturday to work with struggling shortstop Starlin Castro.
In the Cubs' 6-2 loss to the Pirates later in the day, Castro went 0-for-3. His batting line now stands at .247/.287/.344, and he has only 3 hits in his last 44 at-bats.
Manager Dale Sveum is a hitting coach by trade, and he sees one major flaw with Castro: too much movement.
"It's an everyday battle obviously, right now, with whatever mechanics are bad or if it's in the head," Sveum said. "He's a cut-and-slasher who's going to swing the bat. I'd like to see him back to where he was in 2010 and 2011 when there was a lot less movement going on. He thinks they're the same mechanics, but they're not the same mechanics as what he came up in the big leagues and in 2011.
"It might look the same, but it's way more movement as the pitch is being delivered."
Sveum cited several things as being different from 2010 and 2011 with Castro, whose hitting coach from 2010 through last summer was Rudy Jaramillo, who was fired by the Cubs.
"There's the leg kick, way more open stance and a lot more movement in the hands," Sveum said. "With the naked eye, it all looks a little bit the same, but it's not the same. In his first two seasons, he was around a .770 OPS with that, just a lot less movement was going on.
"With his hand-eye coordination, when you nail it down to a lot less movement, he should be able to hit every pitch because the rest of his mechanics are right there with some of the best hitters, the way his backside works, how he gets to a stiff front side. The hand-eye coordination, period, adds up to a guy that can hit."
Castro did hit the ball hard Saturday, but he showed some frustration at the plate after he lined out to shortstop in the fifth inning.
Right-hander Jeff Samardzija fell to 3-7 with a 3.18 ERA as he worked 6 innings and gave up 8 hits and 4 runs. Pedro Alvarez hit a 2-run homer in the fourth to give the Pirates a 4-0 lead.
"I thought I made some adjustments at the end, after the Alvarez home run, that were pretty important," Samardzija said. "I got back to my fastball command and started throwing my slider for a strike. The splitter was up all day."
Ian Stewart, playing third base for Class AAA Iowa, hit 3 home runs, drove in all 8 runs and tied an Iowa franchise single-game record for RBI in an 8-5 win over Round Rock on Saturday. He was taken off the 40-man roster earlier this year after rehabbing a quad injury.
"That's probably the best game I'll ever have in my career," he told the Des Moines Register.
Reliever Kyuji Fujikawa is scheduled to see Dr. James Andrews on Monday, with Tommy John surgery on his right elbow scheduled for Tuesday.
There is no timetable yet on a rehab assignment for reliever Shawn Camp, who has been on the disabled list since May 22 with a sprained right big toe. Camp has thrown out of the bullpen.