Thanks in large part to the play of their right fielder, the Rockies have won four of their last six heading into Monday night's opener of a three-game set in Arizona against the struggling Diamondbacks.Barnes, who is hitting a major league-best .545 since April 18, provided the spark at the top of the order Sunday, getting three hits and driving in a pair of runs to lead the Rockies over the Los Angeles Dodgers 6-1."We feel really good about it," said Barnes, who hit .214 through the first three weeks of the season. "We don't take anything for granted and we keep battling every day."Charlie Blackmon, Justin Morneau and Nolan Arenado each went 2 for 4 and scored a combined six runs, while Josh Rutledge hit a three-run homer for Colorado (14-12).The Rockies will look to keep it going behind left-hander Franklin Morales, who has been giving up the long ball this season but not much else. He has allowed only one run in each of his last two starts -- both on solo homers -- to earn a pair of victories while tossing a combined 13 innings.Morales (2-1, 3.86 ERA) has struggled during his career in Arizona, allowing 10 runs and 15 hits in 16 1/3 innings at Chase Field. Six of his nine appearances at the ballpark were out of the bullpen and he hasn't started there since April 21, 2009.He will be opposed by Wade Miley (2-2, 4.50 ERA), who has thrived in his career versus the Rockies. The left-hander is 7-0 against Colorado, including a 5-3 win April 6 when he went eight innings and allowed just two runs."I don't know," Miley said when asked of his success against the Rockies. "My mentality is the same against these guys as it is against anyone else. I was just trying to keep the ball down. You know down is good against this team. They're an aggressive team. That's a really, really good lineup over there."You don't want to make mistakes to those guys."The Diamondbacks (8-20) dropped two of three against Philadelphia over the weekend, continuing their struggles in their own ballpark. Arizona is 2-13 at home, allowing 5.9 runs per game while averaging just 3.3. Opponents are reaching base on 34.4 percent of their at-bats at Chase Field, the highest of any National League team.Arizona's lack of clutch hitting was the latest culprit Sunday in a 2-0 loss that was already its fourth shutout this season. The Diamondbacks left all six of their runners on base to waste a strong outing by Brandon McCarthy, who struck out 12 in seven innings."(McCarthy) threw a heck of a game for us," manager Kirk Gibson said. "We need to get synced up and play a total game."The Rockies won two of three versus the Diamondbacks earlier this season in Denver. However, Arizona was 8-2 last season in Phoenix against their NL West rivals.