MILWAUKEE -- Cubs Minor League pitcher C.J. Edwards, ranked No. 4 on MLB.com's Cubs' Top 20 Prospects list, underwent an MRI on Friday, which revealed some fatigue and inflammation in his right shoulder. The good news is there was no structural damage.
Edwards, 22, was examined in Chicago on Friday. He posted on his Twitter account: "Great news today rest then back at again #cubs#smokies#stilllivingmydream."
Cubs manager Rick Renteria said Edwards will begin a throwing program in a couple weeks.
"He's obviously somebody we really like, and this is just a little setback and he'll be fine," Renteria said.
The right-hander had a 2.61 ERA in four starts for Double-A Tennessee. On Sunday, he gave up two runs on three hits and two walks over six innings against Birmingham. Edwards felt some discomfort in his shoulder during a side session.
The slender right-hander was one of four players acquired from the Rangers for Matt Garza last July.
Edwards made one start in Spring Training for the Cubs and gave up three runs on four hits and three walks over 2 2/3 innings.
On a roll, Starlin slotted in cleanup spot
MILWAUKEE -- Cubs shortstop Starlin Castro has batted second, third, fifth and sixth this season, and on Friday, he was inserted into the cleanup spot for the second time in his career.
Castro has been on a roll, hitting safely in 14 of his last 19 games, and batting .307 dating back to April 3. That's part of the reason he was hitting fourth for the first time since Aug. 18, 2012, when he did so in the second game of a doubleheader in Cincinnati.
"We're trying to split up the lefties," Cubs manager Rick Renteria said of batters Anthony Rizzo, Luis Valbuena and Nate Schierholtz. "[The Brewers] do have three lefties in the bullpen, and with one less guy on the bench, we want to be able to give ourselves a chance to manuever through some of the lefty-lefty matchups by stacking, which we've been doing."
The Cubs decided to go with a 13-man pitching staff rather than add another outfielder when Justin Ruggiano went on the disabled list with a left hamstring strain, injured Wednesday.
Veras day to day with sore left oblique
MILWAUKEE -- Cubs reliever Jose Veras has a sore left oblique and is day to day, manager Rick Renteria said Friday.
Veras pitched on Thursday against the D-backs, and gave up two runs in one inning. It was his sixth appearance this season. The right-hander lost his job as the closer after blowing a two-run lead on April 11 against the Cardinals, and Thursday was only his second appearance since then.
"Veras is a little sore with his left oblique, and hopefully he'll be OK," Renteria said. "He's been working really hard and developed a little soreness. He's a very hard worker. We'll monitor it and see how he's doing."
The Cubs have eight relievers in the bullpen, including Veras, after adding lefty Zac Rosscup and right-hander Neil Ramirez on Thursday.
• Wrigley Field has hosted baseball, football, boxing, hockey, soccer and even ski jumping. On Saturday, the Northwestern women's lacrosse team will play USC at the ballpark.
The Wildcats have won seven NCAA titles in the last nine seasons and take a 9-5 record into the game. It will be the first lacrosse game ever at Wrigley.
All tickets are $10 with first-come, first-served seating. Tickets can be purchased in advance by calling (888) 467-8775 or bought Saturday at the Wrigley Field ticket office.
• In Minor League news, Tsuyoshi Wada struck out six over five shutout innings in Triple-A Iowa's 9-0 win over Colorado Springs on Thursday. Dan Vogelbach, ranked No. 10 on the Cubs' Top 20 Prospects list, had four hits, including a home run, and an RBI in Class A Daytona's 7-3 win over Brevard County. Albert Almora, No. 3 on the prospects list, added two hits.
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.