© 2014 MLB Advanced Media, L.P. All rights reserved.

6/22/2014 2:33 P.M. ET

Cubs taking patient approach with Bonifacio

CHICAGO -- Emilio Bonifacio has been on the disabled list with a strained right oblique for more than a week, but has yet to begin baseball activities. Cubs manager Rick Renteria said the team is in "wait-and-see" mode with Bonifacio, who is progressing with his treatment.

"He's feeling better. He's not feeling any discomfort anymore," Renteria said. "He's doing some exercises, lower extremity exercises, some movement exercises, but we're still waiting to see in the end once the strength starts coming back and what we'll do on how we'll proceed with him."

The Cubs are being cautious with Bonifacio out of necessity. Oblique injuries are tricky because they can resurface if not given enough time to heal. It could be a while before Bonifacio does something like swinging a bat.

"It could flare up. Those types of things can become a little chronic," Renteria said. "Take care of them the right way right from the get go, and I think we're trying to be as patient and proactive as possible to make sure that he recovers with no repercussions later."

No matter spot in lineup, Valbuena getting on base

CHICAGO -- Luis Valbuena's ability to get on base consistently has provided manager Rick Renteria with some needed lineup flexibility.

When Emilio Bonifacio went on the disabled list with a right oblique strain last Friday, it created a void at the top of the order. Renteria has used several players in the leadoff spot, including Chris Coghlan and Valbuena, who hit leadoff in five consecutive games.

Though he posted a .217/.280/.304 line in those five games, his ability to move up and down the lineup has been a bonus for the Cubs. Valbuena has posted a .330/.395/.527 line since May 13 entering Sunday's action, placing him among the National League leaders in on-base percentage in that span. 

"He's been very valuable. I think the last couple years that he's been here, even last year when he split time, he did a nice job," Renteria said. "I think he's had opportunities to show that he can get on base. Obviously, he's had some big hits for us, but it's big because you get a line started and you keep it moving, so to speak. He's been able to get on base or drive in runs or get one by swinging the bat."

Each category of Valbuena's .276/.371/.442 line are career highs.

"I don't mind. Leadoff, whatever Renteria wants me to do, I'll be ready," he said. "If I'm hitting fourth, fifth, sixth, if I have to bunt, I want to bunt. I have to do my job, no matter what the position in the lineup."

Valbuena said his approach is the same no matter where he's hitting: see pitches, work the count, and get on base any way possible. He sees 4.16 pitches per plate appearance, fourth in the National League entering Sunday's action.

"I think that what's most important when guys have that type of on-base [percentage]: One, they have a really good understanding of the strike zone and that's one thing Val's always had that throughout his entire career," said hitting coach Bill Mueller. "Then on the other side of that, he's been using that whole field as much as possible this year, where he's really bought into left-center.

"It's basically that combination of using the whole field with his eyes [that has] really helped him sustain those types of numbers and get off to a pretty good start here."

Castillo activated from DL; Whiteside designated

CHICAGO -- Catcher Welington Castillo was activated from the disabled list prior to Sunday's series finale with the Pirates. In a corresponding move, Eli Whiteside was designated for assignment.

Castillo went 3-for-8 with an RBI, two walks and a stolen base in two rehab games for Triple-A Iowa.

Backup John Baker was given the starting nod, because Castillo was still on his way to the ballpark from Triple-A Iowa when the lineup was posted, but Castillo was available off the bench.

Castillo was placed on the DL on June 3 with a strained left rib cage. He should help restore some offensive production to the catching spot, as Whiteside and Baker averaged a .147/.183/.168 line in Castillo's absence. Of the 18 games Castillo missed, Baker started 11 and Whiteside seven. Castillo was hitting .242/.287/.385 in 43 games entering Sunday's action.

"More than anything, just having him back, you know, he's been with the club here now developing as a catcher and being a part of the Cubs moving forward," manager Rick Renteria said. "Just having him back and healthy, being able to get out there with his teammates will be good to have."

Whiteside could return to Triple-A Iowa if he clears waivers. Renteria hopes that's the case.

"He's done a nice job for us," Renteria said. "He's an excellent receiver -- a nice game for us [Saturday]. He helped the transition while Weli went down and continued to have the ball moving forward, and from a very selfish perspective, I think we as an organization hope he clears."

Worth noting

• If the Cubs homer on Sunday, they will have homered in nine straight games, which last happened July 12-24, 2013.

• With his 15th home run of the season on Saturday, Anthony Rizzo became the 12th lefty Cubs hitter to reach that mark prior to the All-Star break, and the first since Carlos Pena hit 19 prior to the 2011 break.

• The Cubs and Pirates on Sunday wore retro uniforms from 1953, which was Ernie Banks' debut season with the Cubs. Chicago is 8-4 when wearing throwbacks.

• In addition to the Castillo/Whiteside move, the Cubs selected the contract of left-hander Tsuyoshi Wada and optioned him to Triple-A Iowa, where he has been pitching all season. The club's 40-man roster is full.

Joe Popely is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.