Robertson is 6-0 with a 3.43 ERA in his last 10 starts. The 26-year-old right-hander leads the Astros with a 7-3 record despite a 5.15 ERA.
Robertson’s six-game winning streak is the longest by a Houston rookie since Roy Oswalt did it twice in 2001.
“I’ve found a little groove,” Robertson said. “I’m just going to try to minimize my mistakes and keep doing what I’m doing.”
The Reds have dropped two straight to the Astros and six in a row overall.
Cincinnati’s losing streak is its longest since it dropped eight straight from June 16-24, 2002. The Reds have just 11 hits in the first two games of the series.
“You are going to go through periods like this. We are in a little rut,” Cincinnati’s Aaron Boone said. “I don’t think its a big deal but, unfortunately, we are not scoring a bunch of runs right now. But I think we will come out of it.” We stink right now. Pick an area, offense, defense and pitching.”
Morgan Ensberg hit a two-run homer to lead Houston to a 6-3 victory Tuesday.
Reds outfielder Ken Griffey Jr. homered, but also agreed with Boone.
“It is just one of those things that every team goes through,” he said. “The Astros went though it when they were swept in Pittsburgh. It’s just critical when you are in your division. The good thing is we have a couple of more games with these guys and we can turn it around.”
Adam Dunn also homered for Cincinnati.
The Reds committed two more errors, leading to three unearned runs. Cincinnati has committed a major league-leading 85 errors.
STANDINGS: Reds - 4th place, 5 1/2 GB, NL Central. Astros - 1st place (tied), NL Central.
REDS PROBABLE STARTER: Danny Graves (4-8, 4.79 ERA). The right-hander is 1-2 with a 3.43 ERA in his last three starts. Graves went seven innings, allowing four runs and four hits in a 6-2 loss to the New York Mets on Saturday. He has given up 17 home runs in 18 appearances, including 17 starts.
ASTROS PROBABLE STARTER: Robertson (7-3, 5.15 ERA). Robertson beat Cincinnati 4-1 on April 10, holding the Reds to one run and two hits while striking out a season-high eight in seven innings. He hasn’t lost in 12 starts since April 25 against the New York Mets. Robertson allowed three runs and seven hits over 7 1-3 innings to earn a 7-3 against Milwaukee on Thursday.
OFFENSIVE LEADERS: Reds - Sean Casey, .295 avg.; Dunn, 25 HRs and 55 runs; Austin Kearns, 58 RBIs; Boone, 12 SBs. Astros - Jeff Kent, .313 avg.; Ensberg, 17 HRs; Lance Berkman, 54 RBIs and 56 runs; Adam Everett, 6 SBs.
SEASON SERIES: Astros, 4-1.
STREAKS AND NOTES: Reds - OF Dunn is batting just .216 with 95 strikeouts in 83 games. He struck out 170 times in 158 games last season. …1B Casey left Tuesday’s game in the fifth because of a strained right groin. He is day-to-day. … 2B D’Angelo Jimenez went 1-for-3 Tuesday in his Reds’ debut. Jimenez hit .255 with seven home runs and 26 RBIs in 72 games with the Chicago White Sox before getting traded to Cincinnati on Sunday.. Astros - OF Berkman is 3-for-10 lifetime against Graves with two home runs and seven RBIs. … OF Ensberg is batting .324 (33-for-102) in his last 34 games with 12 homers and 25 RBIs. … LHP Billy Wagner leads the Astros with 23 saves. He is Houston’s third pitcher to be a three-time All-Star, joining Mike Scott (1986, 1987, 1989) and Dick Farrell (1962, 1964, 1965).
ROAD/HOME RECORDS: Reds - 19-26 on the road; Astros - 28-17 at home.
INJURIES: Reds - OF Wily Mo Pena (hamstring), 15-day DL; LHP Kent Mercker (back), 15-day DL; LHP Gabe White (groin), 15-day DL; RHP Luke Prokopec (elbow), 60-day DL. Astros - IF Jeff Kent (shoulder), 15-day DL; IF Jose Vizcaino (wrist), 15-day DL; LHP Carlos Hernandez (shoulder), 15-day DL; RHP Rodrigo Rosario (shoulder), 15-day DL; RHP Brian Moehler (elbow), 60-day DL.