PORTLAND — Brock Holt came to the Boston Red Sox in 2013 as a middle infielder, having split time between second base and shortstop as a minor leaguer in the Pittsburgh Pirates’ organization. Holt has more than just a middle infielder for the Red Sox the past two seasons, playing every position except pitcher and catcher in both 2014 and 2015.

That’s a path to the major leagues that Portland Sea Dogs infielder Mike Miller hopes to emulate.

Miller, who spent time with the Sea Dogs and the Triple-A Pawtucket Red Sox in 2015 and is back in Portland to start this season, has spent time at second, third and short since being drafted by the Red Sox out of Cal Poly San Luis Obispo in 2012. The 5-foot-9 right-handed hitter then ventured to the outfield for the first time while playing for the Surprise Saguaros of Major League Baseball’s Arizona Fall League in 2014.

Two games in left field turned into five games in center for the Paw Sox last year. Then in spring training this year Miller “got some work” at first base to equal Holt’s versatility.

“The more positions you play the better,” Miller said. “If someone goes down and you can play multiple positions, it’s only going to benefit you.”

Miller started his 2015 season in Portland, then was promoted in late March to Pawtucket. He hit .273 in 40 games for the Sea Dogs last year, but it was his glove as much as his bat that earned him the promotion.

“It was fun. Different ballgame up there,” Miller said of playing in Pawtucket. “You get a lot of older guys up there that have been around for a long time, so there’s definitely a learning curve.”

Miller’s batting average dropped to .219 in 74 games at the Triple-A level, facing many pitchers with major-league experience.

Like all minor-leaguers have to do when they make the jump to a higher level, Miller had to adjust. He said he had to be smarter at the plate.

Despite finishing last season in Pawtucket, and playing more games there than in Portland, Miller found himself right back with the Sea Dogs to start another season. It was a demotion of sorts that can be hard for a player to swallow. Miller, who has never been a highly-ranked prospect, instead has taken it in stride.

“Obviously your goal is to go up,” Miller said. “I spent some time in Pawtucket last year. That’s out of my control. They got good players everywhere you go, so as long as I’m still playing I’m happy.”

Miller added that not being a top prospect doesn’t mean a player isn’t good. Holt, who like Miller was picked in the ninth round of the MLB draft (Holt was drafted in 2009), was never a top prospect for the Pirates. Yet the 5-foot-10 utility player was named an All-Star for the Red Sox in 2015.

Prospect labels don’t mean much on the field, according to Miller. Holt has proven that. Miller would like to do the same. But for now it’s just about trusting the process.

Miller is off to a slow start to this season, batting just .217 through the Sea Dogs’ first six games entering play Wednesday. On the flip side, he’s already played three positions (second, third and short) in those six games, and could be one or two injuries in Boston or Pawtucket away from getting another promotion.

While Miller has enjoyed his time in Portland, Pawtucket — and hopefully someday Boston — is where he wants to be. Where he plays on the field, however, doesn’t matter much to Miller.

“I just want to be on the field playing. You love the game, you don’t care where you play,” Miller said.

wkramlich@sunjournal.com