CHICAGO -- The Cubs added a fresh arm to the bullpen on Saturday, recalling right-hander Jae Kuk Ryu from Triple-A Iowa and optioning righty Angel Guzman to the Minor League team.

Guzman, 24, was 0-2 with a 7.00 ERA in four starts for the Cubs this season, including Friday's game against the Padres in which he gave up two runs on three hits and five walks over three innings. The walks have been a problem. The young right-hander issued 16 free passes over 18 innings in his four starts.

"We just thought Guzzie needed a little more time to serve his apprenticeship more in the Minor Leagues to get his control together and get back and win," Cubs manager Dusty Baker said. "When we call him back, he'll be ready. He was here more out of necessity than whether he was ready or not. He made some quality pitches and sometimes he'd lose control of the strike zone."

Ryu was assigned to the bullpen and will be used in long relief. He was 1-3 with a 3.21 ERA in seven starts for Iowa, with 34 strikeouts over 42 innings. Ryu, 22, has pitched six or more innings in four of his seven starts. His first appearance will be his Major League debut, and he's the fourth rookie pitcher to be used by the Cubs this year.

Ryu joins the team during some some tough times. The Cubs entered Saturday's game having lost 10 of their last 11.

"We're on a day-to-day thing right now," Baker said. "We're trying to win daily. We're just trying to get a streak going."

Backstop: Catcher Michael Barrett did not start Saturday, but it had nothing to do with his spat with the Padres. Barrett exchanged words with San Diego leadoff man Dave Roberts on Friday.

Roberts had stolen third base with a three-run lead and scored on a Mike Cameron double. Barrett said something to Roberts as he crossed home plate, and the Padres players came out of the dugout to defend their left fielder. There was no physical contact between the two, but the umpires issued a warning to both sides.

Henry Blanco started behind the plate on Saturday for the Cubs. Blanco has thrown out three of five base runners, while Barrett has thrown out six of 43 (14 percent).

"Michael's been doing a lot of catching; he caught a lot on the coast," Baker said. "Plus, if I could give him today off, and he'll have [Monday] off, then he'll be strong."

Baker said Barrett's outburst on Friday was "just frustration and anger."

Growing pains: Both Matt Murton and Ronny Cedeno learned from their mistakes. Cedeno took a relay throw on Friday and thought he'd called for time, but he apparently didn't check with the umpires. Cedeno threw the wet ball back to the dugout and two runners advanced on his error.

"Ronny felt terrible yesterday. That was a young mistake," Baker said. "He'll learn from it. He felt terrible -- I thought he was going to cry when I saw him."

The Cubs coaches talked to Murton about the rules of the ivy. Next time a ball goes into the greenery and Murton can't see it, he'll raise both arms.

"I guess you should just leave it there," Murton said. "If they don't give it to you and they run the bases, I don't know who's fault it would be. You don't want to assume they're going to give it to you. I don't know the rules. How deep does it have to be [in the ivy]?"

Murton saw the ball fall and he could see it -- plus none of the umpires came out to check.

"I've been taught to shoot first and ask questions later," Murton said. "I put my hands up, I let them know it was in the ivy. Then from there, when it starts trickling out, you've got to play it. From now on, they said just leave it there."

Said Baker: "They're both young."

Dress code: Don't expect to see Scott Williamson in long sleeves again. The Cubs reliever had to have his long sleeves cut off on Friday because home plate umpire Bruce Dreckman asked him to. The red pattern on the sleeve apparently was distracting.

"I guess it's up to the umpire or the opposing team now," Williamson said. "It doesn't bother me. I don't like to pitch in sleeves anyways."

Funny thing is, the shirt is specifically designed for pitchers, and Williamson's had thicker material on the right sleeve. Will Ohman's shirt, on the other hand, is thicker in the left sleeve. Both shirts are approved by Major League Baseball.

"[Dreckman] said, 'You can't pitch in that. You have to take it off,'" Williamson said. "It was kind of humorous -- I said, 'Do you think I have another shirt in my back pocket here?' So I just cut 'em."

Extra bases: Former Cubs pitcher Dave Otto was one of the left-handed batting practice pitcher candidates, and he threw on Saturday. Hitting coach Gene Clines is handling the auditions. ... Barrett and Jacque Jones will use pink bats in Sunday's game as part of Major League Baseball's celebration for Mother's Day. Todd Walker will use his pink Louisville Slugger bat during batting practice. ... Murton will be host to members of a Chicago area Boys and Girls club on Wednesday at Wrigley Field. Murton was given access to one of the mezzanine suites for the game, and rather than use it for himself, he wanted to donate it to a youth group. ... If you're looking ahead to the Cubs' three-game series against the White Sox, starting Friday, the likely pitching rotation will be: Greg Maddux, Rich Hill, and Carlos Zambrano.

Minor matters: Felix Pie had two hits in Iowa's 2-0 loss to Colorado Springs. Pie has hit safely in six of his last eight games. ... Micah Hoffpauir hit a two-run home run to help West Tenn beat Montgomery, 11-2. Hoffpauir leads the Southern League with 10 homers and has 30 RBIs. Luis Montanez and Chris Walker each had three hits. J.R. Mathes threw six scoreless innings for West Tenn. ... Matt Weber gave up one run on four hits over five innings in Daytona's 3-1 win over Fort Myers. ... Peoria's game against South Bend was postponed because of rain.

On deck: Hill will close the Cubs' three-game series against the Padres on Sunday at 1:20 p.m. CT. The rookie left-hander will be making his third start of the season. The game will be broadcast on WGN Radio and WGN TV.