By JEFF BARTL
(AP) -- The Colorado Rockies' offense has been clicking through the first three games of their series with the Houston Astros.
Bud Norris seems capable of slowing it down - particularly since he won't have to face Troy Tulowitzki.
The Astros' hurler looks to cap an unbeaten month while helping Houston avoid a sweep in Colorado on Thursday night.
The Rockies (20-29) have scored 29 runs while winning three straight over the Astros, who have dropped a season-high five consecutive contests. After sweeping a doubleheader Monday, they hit five homers - three by Carlos Gonzalez - in a 13-5 victory Wednesday.
Michael Cuddyer hit a first-inning grand slam and Dexter Fowler, who is 9 for 14 with two homers in the series, hit a three-run shot in the sixth.
Gonzalez went 4 for 5 in his first career three-homer game, and he's hitting .419 with six homers over his last 10 contests.
"All I've been doing is trying to put good swings on the ball," Gonzalez said. "Obviously, I'm not looking for a home run. I'm just looking to hit the ball hard and just make sure it's in the strike zone."
Colorado, though, will have to continue its hot hitting without Tulowitzki, who left in the seventh inning with a strained left groin and was placed on the disabled list prior to this game.
His absence certainly won't help the Rockies against baseball's stingiest pitcher over the last month.
Norris (5-1, 3.34 ERA) is 4-0 with a 1.17 ERA in May - the best mark in the majors for the month. He hasn't lost in his last six starts since allowing a season-high seven runs against Milwaukee on April 24.
The right-hander didn't have his best stuff Saturday against the Los Angeles Dodgers, though, giving up three runs and eight hits in 4 2-3 innings as Houston lost 6-3 on a walk-off three-run homer.
Norris also didn't factor in the decision April 8, when he allowed two runs and struck out eight in seven innings of the Astros' 3-2 win over Colorado.
The Rockies counter with Jeremy Guthrie (2-3, 5.31), who has allowed six runs in four of his seven starts - including his last two. Only two of the six were earned as he gave up a season-high 10 hits over five innings of a 10-3 loss at Cincinnati on Saturday.
"When Jeremy Guthrie is commanding the strike zone, the ball is pounding down, the fastball is well-spotted and he pitches ahead, which helps his secondary pitches immensely," manager Jim Tracy told the team's official website. "We're just not getting that right now."
The Rockies aren't getting much from the rest of their pitching staff, either. Colorado has the NL's worst ERA at 5.18.
Guthrie has had trouble matching the success from his first start of the season April 6, when he allowed three runs in seven innings of a 5-3 victory in Houston.
The Astros (22-28), though, have lost six consecutive games at Coors Field - their longest skid in Denver since dropping all seven at Mile High Stadium to the expansion Rockies in 1993.
Houston's Chris Johnson, who went 3 for 3 on Wednesday, is hitting .393 over his last nine games.
Updated May 31, 2012