Royals head to Chicago hoping to end four-game skid

CHICAGO -- Fresh off being swept by the St. Louis Cardinals, the Kansas City Royals enter aweekend series at the Chicago White Sox trying to figure out how to solve their bullpen problem.

The Royals have lost four straight games and nine of their past 11. Theirtroubles stem largely from the bullpen, which has been taxed during the recent slide. In the four losses to the Cardinals this week, only one starter managed to pitch at least six innings. That took its toll on manager Ned Yost's relief pitchers, who allowed 19 runs in 16 innings.

After an 8-6 loss Thursday at Busch Stadium, Yost admitted something has to change -- and soon.

"It's kind of a bullpen slump, a little bit, but it's a good bullpen," Yost told the Kansas City Star. "They'll fight their way through it."

Danny Duffy (7-7, 3.48 ERA) gets the start for the Royals in the opener Friday night. The left-hander won two consecutive starts before a no-decision and then a loss in his most recent outing, when he allowed three runs in 5 2/3 innings against Seattle.

Duffy is 6-4 with a 4.08 ERA in 18 games (16 starts) against the White Sox. However, in two outings against Chicago this year, he is 0-2 with an 11.17 ERA, having allowed 12 runs on 19 hits in 12 2/3 innings.

Duffy will face right-handerReynaldo Lopez, the latest White Sox minor leaguer to make the transition to the big-league stage.

Lopez will be officially called up from Triple-A Charlotte on Friday. He replaces Mike Pelfrey, who was moved to the bullpen, in the rotation.

"Everybody has kind of been anticipating his arrival as we wait for a lot of the other guys that are going to be developing over the course of the next couple of years to get here," White Sox manager Rick Renteria said Thursday before the White Sox finished off a sweep of the Houston Astros with a 3-2, 11th-inning walk-off victory. "Certainly, we're all looking forward to getting him out there on the hill to see how he's doing."

Lopez, 23, went 6-7 with a 3.79 ERA and 131 strikeouts in 22 starts this season for Charlotte. He was 5-3 in 11 starts with the Washington Nationals last season, when he struck out 42 in 44 innings and had a 4.91 ERA.

He was acquired last offseason in a deal that sent center fielder Adam Eaton to Washington. Last week, Lopez said he was prepared to make the move to the major leagues and become a full-time part of the White Sox rotation.

"I feel like I'm ready physically and mentally to pitch in the majors," Lopez said through a team interpreter. "Yes, it has been a little difficult because you dream about pitching in the majors.

"When you're doing your job and things are going well, then you want to be there right away. But you also know you have to be patient. That's one of the things I've been trying to show to the organization -- that I can be patient, too."

Lopez will oppose Kansas City for the first time.