Chen, a 34-year-old native of Panama, won five consecutive starts between Aug. 7 and 28 to improve his season record from 5-5 to 10-5.
He defeated Cleveland, 2-1, with 7 1/3 innings of five-hit ball for victory No. 10, but has since dropped two starts in a row - home with the Indians and at Oakland - while allowing 16 hits and 11 runs in 11 1/3 innings.
The Royals have won six of his last 10 starts.
Chen is just 1-4 lifetime against Minnesota in 15 games - five starts - while allowing 59 hits and 31 earned runs in 42 1/3 innings.
He'll be opposed by Twins veteran Carl Pavano, who's won two straight decisions - his only wins in his last 10 starts.
The 35-year-old fell to 6-11 on the year with a 6-4 loss to Detroit on Aug. 27 but is 2-0 in September, defeating the Los Angeles Angels of Anaheim and the Chicago White Sox while surrendering 17 hits and four earned runs in 12 innings.
Minnesota is 4-6 in his last 10 starts.
Pavano is 8-6 in 16 career appearances against the Royals with a 5.90 earned run average across 93 innings.
On Sunday in Detroit, Doug Fister threw seven innings of three-hit ball and Jose Valverde struggled before earning his club-record 43rd save, as the Tigers held on for their ninth straight win in a 2-1 victory over Minnesota.
Scott Diamond (1-4) pitched well in defeat, allowing two runs -- one earned -- on seven hits in six innings. He walked four and struck out four for the Twins, who have lost eight of their last nine games.
In Seattle, Alex Gordon's RBI double in the seventh helped Kansas City take a 2-1 win over the Mariners to split a four-game series.
Gordon also had an RBI double in the third while Alcides Escobar had two hits and scored a run for the Royals, who won the last two games of this set. Everett Teaford (1-0) pitched five innings of three-hit ball while striking out five and walking one to get the first win of his career in his first start.
Minnesota is 8-5 against the Royals this season.