(AP) – The Chicago White Sox continue their long stretch against National League opponents with the Washington Nationals. The Nationals have won 11 of their last 12 games, but will face the White Sox without manager Jim Riggleman.

Moments after Laynce Nix’s sacrifice fly Thursday gave Washington (38-37) a 1-0 victory over Seattle for its 11th win in 12 games, Riggleman stepped down as manager.

“We should be celebrating going to Chicago,” general manager Mike Rizzo said. “I’m disappointed that this is a distraction.”

The Nationals are over .500 this late in the season for the first time since 2005, but that was not enough to keep Riggleman happy. He has been working on one-year deals since taking over for Manny Acta in July 2009, and was looking for some long-term security.

“Jim told me pregame (Thursday) that if we wouldn’t pick up his option, then he wouldn’t get on the team bus,” Rizzo said. “I felt that the time wasn’t right for me to pick up the option, and certainly today’s conversation put to me in the way it was put to me, you certainly can’t make that decision in a knee-jerk reaction.”

Riggleman said he requested to meet with Rizzo in Chicago to talk about his contract, but further stated that he would have resigned had that conversation not resulted in some sort of contract security.

“It’s been brewing for a while,” Riggleman said. “It’s not a situation where I felt like I should continue on such a short lease. I just felt if there’s not going to be some type of commitment, then there obviously never will be.”

Bench coach John McLaren will replace Riggleman on a short-term basis.

Despite the stunning turn of events, Washington players are poised not to let this become a distraction.

“It’s not going to change anything in here,” right fielder Jayson Werth said. “We’re the ones that have been winning the ballgames, so we’re going to keep going.”

The Nationals hope to do so against a Chicago club that has won 17 straight interleague series, and swept a three-game set at Washington last season.

“I know they’ve done some good things,” White Sox catcher A.J. Pierzynski told the team’s official website. “They are going to come in here fired up.”

Washington will face former teammate Adam Dunn, who hit 38 homers and drove in more than 100 runs in each of the previous two seasons with the Nationals. Dunn, however, is batting .175 with seven homers, 29 RBIs and an AL-high 91 strikeouts for Chicago.

“It is the most frustrating thing that has ever happened to me,” said Dunn, who has fanned seven times during his current 0-for-12 slump.

Teammate Paul Konerko is far from frustrated, batting .429 with 11 homers and 22 RBIs his last 21 games. He homered in five straight contests before going 0 for 3 in Wednesday’s 4-3 win over the Cubs.

Konerko has never faced scheduled Washington starter Jordan Zimmermann (5-6, 3.08 ERA), who is 3-0 with a 1.32 ERA his last four starts. The right-hander allowed two runs in 6 1-3 innings of a 4-2 win over Baltimore on Saturday.

The White Sox (37-39) counter with right-hander Edwin Jackson (4-6, 4.47), who makes his first start versus Washington while looking for his first win since May 22. Jackson, who allowed four runs in 6 2-3 innings of a 4-1 loss at Arizona on Friday, is 0-1 with a 4.97 ERA in his last four starts.

Werth is 2 for 3 with a double against Jackson.

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