The Kansas City Royals are on the verge of matching their longest winning streak of the season, thanks in large part to superb pitching.
The rotation has been particularly dominant.Bruce Chen looks to keep the Royals rolling with another commanding performance Sunday against the last-place Chicago White Sox.Kansas City (50-51) is on a five-game winning streak for the first time since a season-high six-game run from June 5-10.The Royals' current surge has been powered by their pitching staff, which has compiled a 1.00 ERA. The rotation has been especially excellent with a 0.79 ERA.James Shields tossed seven scoreless innings in Friday's 5-1 win and Wade Davis was even better Saturday, going 7 1/3 while allowing four hits in Kansas City's 1-0 victory.Now it's up to Chen (4-0, 1.97 ERA) to help the Royals complete the sweep. The left-hander has been outstanding in two starts since entering the rotation in place of an ineffective Luis Mendoza, who beat him out for a starting spot in spring training.The only run the 36-year-old has allowed in 12 innings of two starts came on a solo homer in Tuesday's 3-2 win over Baltimore."His fastball -- he'll throw one at 83 (mph) and then one at 87, and the 87 looks like 94 mixed in with the slow curveball, the changeup, the two-seamer. So he does a great job of on and off the gas with his velocities," manager Ned Yost told the team's official website.Chen is 3-1 with a 3.60 ERA over his last five games -- four starts -- versus Chicago. However, that defeat came in his most recent visit to the South Side on Sept. 8, when he surrendered five runs and three homers in six innings of a 5-4 loss.The White Sox (40-61) haven't been nearly that productive at the plate lately, getting 14 hits in this series with their only run coming on a Conor Gillaspie's solo shot Friday.Gordon Beckham, 0 for 6 in this series, is mired in a five-game slump during which he's gone 1 for 21. He had been hitting .396 in the 12 games prior to this stretch.Beckham is 4 for 27 with a homer against Chen.Hector Santiago (3-6, 3.38) will take the mound hoping to replicate his most recent start against the Royals. He went a season-high eight innings in Kansas City on June 21, allowing three hits and a run in a 9-1 win.He's 0-1 with a 4.18 ERA in five starts since.Santiago was charged with a 6-2 loss to visiting Detroit on Tuesday, allowing six runs -- three earned -- with six strikeouts and a career high-tying five walks in six innings. The defense didn't provide much help with a season-high four errors.He may not have to deal with Lorenzo Cain, who has three hits and two RBIs over the past two games. The center fielder exited in the eighth inning Saturday due to tightness in his left groin after crashing into the outfield wall while taking a hit away from Jeff Keppinger in the seventh."He's got a little bit of a groin strain, why we took him out," Yost said. "He's day to day. Probably rest him (Sunday) because we've got an off day on Monday, grab him two days right there."