McCutchen looks to put on another hitting display at Coors Field on Wednesday when the Pirates and Colorado Rockies conclude their three-game set.McCutchen's .374 average is the highest in baseball by 19 points over the Los Angeles Angels' Mike Trout, and the center fielder's 65 RBIs are one off Carlos Beltran's NL lead.He has taken a huge step forward after hitting just .259 last year, and his next home run will match his career-high total of 23 from 2011. McCutchen has gone deep six times in his last six games, and he's hitting .500 with nine homers, 19 RBIs and 24 runs in his past 16 contests, with the Pirates (50-40) winning 12 of those."He's doing things that are impressive," manager Clint Hurdle told the team's official website. "He's found a stroke with which he is in a good place. It's been fun to watch."Visiting Denver has kept McCutchen red hot. He has four hits while Pittsburgh and Colorado (35-55) have split the first two games of this series, and he homered for the third time in his last five games at Coors Field in Tuesday's 6-2 win as the Pirates became the fourth team in the NL to 50 wins."It's a mile marker along the way," Hurdle said. "There's a bunch of people in there who planned on getting there earlier than we did."The Pirates are second in the Central, one game back of first-place Cincinnati.Hurdle hopes James McDonald (9-3, 2.59 ERA) can rebound from one of his worst performances of the season and perhaps pull Pittsburgh even with the Reds.The right-hander, who has already matched his win total from 31 starts last year, allowed a season-high five runs along with five walks and eight hits in 4 2/3 innings while not getting a decision in Friday's 10-7 loss at Milwaukee. He had won his previous four starts behind a 2.51 ERA while issuing seven walks in 28 2/3 innings.McDonald is 1-0 with a 2.75 ERA in his last three starts versus the Rockies, but they all came at home. He allowed five runs in five innings in his only previous start in Denver, a win in 2009 with the Los Angeles Dodgers.Colorado has dropped five of seven at home, and giving the ball to Jeremy Guthrie (3-9, 6.14) doesn't seem like the best path to improvement.The right-hander is 1-5 with a 9.23 ERA in eight home games -- six starts. Opponents are hitting .365 against him with 12 homers in 39 innings in Denver.Guthrie's struggles continued Saturday, when he surrendered four runs in the opening inning against Philadelphia at Coors Field. He didn't allow any more runs and ended up pitching 4 2/3 innings, but he still took the loss in an 8-5 defeat."I got the longest scoreless streak of my career at Coors, so there are a lot of positives to build on -- a career low in runs allowed in a start as well," Guthrie told the Rockies' official website. "You've got to take what you can."He was charged with a 9-3 road loss while with Baltimore in his only start against the Pirates on June 21, 2011, allowing six runs and 11 hits in 6 1/3 innings. McCutchen singled and walked twice against him.