The Athletics have won all nine meetings this year with their newest division rivals, and will likely again be without slugger Yoenis Cespedes in Monday night's opener of a three-game series in Houston.Oakland (57-41) has outscored baseball's worst team 68-31 this year, and has won 11 straight in this series and 14 of 15 matchups all-time. Manager Bob Melvin isn't taking that success for granted."You can't just continue to throw your glove out there," Melvin told the Athletics' official website. "They've played well against some good teams this year, too, and they've made some changes along the way that have made them a better team."The Athletics have dominated the Astros (33-64) even though Cespedes is 5 for 25 with no homers and seven strikeouts in the season series.The slugger missed a weekend series in Anaheim due to a sore left wrist suffered in batting practice Friday. It sounds unlikely that the Home Run Derby champion, who hasn't gone deep in 19 straight games, will be in the lineup Monday."Until he actually gets in the batting cage and swings freely and then gets in there for batting practice, he won't play," Melvin said. "I'd doubt tomorrow. We want to make sure he gets in swings on the field."Oakland has had plenty of other hitters step up against Houston. Chris Young has a team-high nine RBIs in the season series, Coco Crisp is 13 for 31 with three homers among 10 extra-base hits with 10 walks and eight RBIs while Jed Lowrie is 12 for 28 with eight RBIs.Those hitters are all slumping now. Crisp is in a 4-for-25 slide, Lowrie a 5-for-31 rut and Young is batting .160 with four hits in his last 25 at-bats.The A's totaled 13 runs in a 4-4 stretch in which they failed to score more than three in any of those contests before Sunday's 6-0 road win over the Angels. Brandon Moss had three hits and Eric Sogard added a two-run homer.Houston has dropped 13 straight at home against AL West foes after getting swept over the weekend by Seattle.The Astros cut veterans Carlos Pena and Ronny Cedeno on Sunday as they look to the future.Shortstop Jonathan Villar, recalled from Triple-A Oklahoma City, will make his major-league debut Monday. The 22-year-old Villar hit .278 with 16 doubles, eight triples, eight homers, 41 RBIs and 31 stolen bases in 90 games for the RedHawks."It's about the fact that Villar's ready and we need to get a long extended look at him," manager Bo Porter told the Astros' official website.Both teams will start left-handers Monday with Oakland pitting Tommy Milone (8-8, 4.24 ERA) against Dallas Keuchel (4-5, 4.62).Milone is 1-0 with a 4.61 ERA in two starts against the Astros this year. He allowed three runs over a career-low 2 2/3 innings in an 80-pitch effort in a 5-0 loss at Pittsburgh on July 10.Keuchel has given up seven runs over 12 innings against Oakland in three 2013 appearances -- one start. Oakland is 19-13 against left-handed starters.