White was acquired from Cleveland as part of the Ubaldo Jimenez deal last month, but had been on the disabled list since May 21 with soreness in his right middle finger. In three starts with the Tribe the first round pick was 1-0 with a 3.60 earned run average.
"I want to have a quality start," said White, who will be making just the fourth start of his big league career tonight. "Go out there for six or seven innings and give this team a chance to win. I'll do my job, and that's the biggest key. I try to do that every time I go out there.
Carlos Gonzalez continued his hot hitting with a homer and three RBI for the Rockies, who have put together three straight wins for the first time since July 27-30.
Chacin (10-10) gave up 11 hits, but just one run to win for only the second time in his last 12 starts.
"Because of walking only one guy and getting outs when he needed them, when there was some traffic out there, he turns it into a very good outing," Rockies manager Jim Tracy said. "The message there is obviously, base on balls, mixed in with the hits that they got during the course of his time out there ... I think it would have been a completely different situation out there."
Gonzalez extended his hitting streak to 10 games. He also has an RBI in seven consecutive contests - tying a career-high - and has driven in 14 runs in that span.
Brian Bogusevic homered among his three hits for Houston, which has lost two straight following a four-game winning streak.
Myers (3-13) was charged with nine hits and seven runs over five innings and lost his seventh straight decision. The right-hander, who hasn't won since June 17 against the Dodgers, a span of 12 starts, entered the night 7-0 in his career vs. the Rockies.
Tonight, the Astros turn to righty Bud Norris, who is 6-8 with a 3.61 ERA. Norris picked up the win on Wednesday against Chicago, as he surrendered three runs and six hits in five innings.
This will be his first ever-appearance against the Rockies.
Houston won four of six from the Rockies last season.