PITTSBURGH -- Andrew Miller has long had the potential to be a frontline starting pitcher in the major leagues.
The 6-foot-7 left-hander was considered one of the top high school pitchers in the nation during his senior season at Buchholz High School in Gainesville, Fla., in 2003 but opted to attend the University of North Carolina. Following an All-America career with the Tar Heels, he was the sixth overall pick by the Detroit Tigers in the 2006 amateur draft.
Yet for all the hype, Miller had a career major league record of 15-26 with a 5.84 ERA coming into this season.
The 26-year-old may finally be reaching that potential with the Red Sox. He made his second straight strong start Sunday since having his contract purchased from Triple-A Pawtucket last week.
Miller allowed two runs, one earned, in six innings as the Red Sox eked out a 4-2 victory over the Pittsburgh Pirates at PNC Park and snapped their four-game losing streak despite getting just six hits. Miller gave up five hits, walked two and struck out four.
"He's a pretty good pitcher," Red Sox manager Terry Francona said. "He's big and tall. He throws hard and has a good feel for the changeup. Maybe we have something here."
The Red Sox just might.
Miller was even better than he was in his Red Sox debut last Tuesday against the San Diego Padres at Fenway Park. In that game, he allowed three runs in 5⅔ innings but did not get a decision in a game the Red Sox won 14-5.
"I thought his command was a little sharper this time," Red Sox catcher Jarrod Saltalamacchia said. "He seemed more comfortable. He hasn't been here long. The longer he's here, the more comfortable and better he is going to be."
The Red Sox decided to take a low-risk gamble on Miller last November, trading left-handed reliever Dustin Richardson to the Marlins for him.
Because Miller was out of minor league options and would have to be subjected to waivers if he did not make the club out of spring training, the Red Sox cut a deal with him. They dropped him off the 40-man roster and re-signed him to a minor league contract that allowed him to become a free agent if he was not in the major leagues by June 15.
"He deserves a ton of credit because he's worked really hard to get to this point," Francona said. "We talked to him, even going back to the winter, about how opening day was not the finish line and that he didn't have to worry about making the club in the spring.
"He's mature enough to know he has some moving parts to his delivery and some things to work on. He went to Triple-A, worked with [Pawtucket pitching coach] Rich Sauveur and made so much progress."
Miller was 3-3 with a 2.47 ERA in 13 games, 12 starts, with Pawtucket. More important than his fine statistics, Miller was able to develop a pregame routine with Sauveur that has worked.
"I had some trouble in the first inning of games, so we wanted to see how we could avoid having to battle through the first inning," Miller said. "It was a matter of getting out, getting the game started and being aggressive early instead of waiting for the third or fourth inning."
Though Miller allowed a sacrifice fly by Ronny Cedeno that enabled the Pirates to tie the game 1-1 in the fourth inning, the left-hander encountered real trouble only in the fifth.
Starting pitcher James McDonald worked Miller for a leadoff walk in a nine-pitch plate appearance, then singles by Garrett Jones and Chase d'Arnaud loaded the bases with none out. Andrew McCutchen followed with an RBI single off third baseman Kevin Youkilis' glove but the Red Sox caught a break when Jones rounded third base too far and was tagged for the first out.
Miller came back to catch Neil Walker looking at a third strike and ended the inning by getting Matt Diaz to ground out. Though the Pirates went ahead 2-1 in the inning, Miller kept things close and the Red Sox rallied with a run in sixth and two in the seventh to avoid being swept in the three-game series.
"He showed a lot of poise," Francona said. "We didn't make some plays behind him, didn't finish some plays, but he never let it bother him. I was really impressed by his poise."
John Perrotto is a baseball writer and occasional contributor to ESPNBoston.com.