The Red Sox are in the midst of deciding which of their minor-league field personnel will join manager Terry Francona’s staff in Boston for the 2010 season.

Former Red Sox bench coach Brad Mills was named manager of the Houston Astros recently, which left a vacancy in Boston.

General manager Theo Epstein and Francona are interviewing internal candidates and have their list down to four, including PawSox manager Ron Johnson, Lowell manager Gary DiSarcina, Red Sox minor-league field coordinator Rob Leary and Tom Goodwin, the organization’s outfield and baserunning coordinator.

It’s possible whoever receives the promotion won’t necessarily be the Sox’ bench coach, as the club could shuffle its current coaching staff if needed.

Pitching coach John Farrell, who turned down an opportunity to manage the Cleveland Indians in order to stay in Boston, will remain in his role, as will hitting coach Dave Magadan.

Third-base coach DeMarlo Hale enters his fifth season in his current role. He could also serve as the bench coach.

First-base coach Tim Bogar enters his second season with the Sox. He has 22 years of experience in pro baseball and was also a candidate for the manager’s position in Houston before Mills was named to the post. If Hale was named bench coach, Bogar could coach third.

Johnson, who has been a minor-league manager for the last 18 years, including the last 10 in the Red Sox organization, could be a first-base coach in Boston. Along with his daily managerial duties for the PawSox, he is the club’s third-base coach.

DiSarcina, a Massachusetts native who played 12 years in the big leagues, has been managing the Spinners for the last three seasons. Given his experience, he could fill a number of roles.

Red Sox bullpen coach Gary Tuck also has experience as a bench coach and could fill that role in Boston, too. If Tuck is moved into that role, Leary, who is a former catcher, has been in the Red Sox organization for almost nine seasons and has also served as the roving minor-league catching coordinator (2002) before being promoted to his current role, could become the bullpen coach in Boston.

Red Sox staff assistant Alex Ochoa just concluded his first year as a pro coach after an eight-year major-league career. His job could also change.

Goodwin has been in the Red Sox organization for the last two seasons after completing his 14-year major-league career. He played for the Dodgers, Royals, Rangers, Rockies, Giants and Cubs.

A decision should be made very soon.

Barajas named assistant trainer

Minor-league players, managers and coaches aren’t the only ones to receive promotions to the majors, as Greg Barajas recently learned.

Barajas has spent 12 seasons as a minor-league trainer, including the last five for the Pawtucket Red Sox. He was recently promoted to Boston and will serve as assistant trainer for the Red Sox under Mike Reinold.

During his tenure with the PawSox, Barajas earned the International League’s Athletic Trainer of the Year award in 2007.

Now he’s taking his skills to the big leagues.

“It’s a dream come true for me,” he said from his home in Arizona. “Getting into the major leagues, in general, has definitely been one of my career goals from when I first started athletic training. It’s been dream I’ve been pursuing for 12 or 13 years, at least.”

He’s already planning his transition to Boston logistically, but from a work standpoint it will be a smooth one. He’s worked with most, if not all, Red Sox players either in the minors, during spring training or during rehab assignments. This is definitely a comfortable situation for him because of his experience.

“My job is changing venues, but I’m very comfortable working with the guys,” he said. “I’m very comfortable with the organization and the guys, and I think that’s a big plus for my job.”

Former Red Sox head trainer Paul Lessard was recently let go by the team after four seasons in Boston. Reinold, who was the assistant trainer/rehab coordinator, is now head athletic trainer.

Westmoreland nearly fully recovered

Red Sox prospect Ryan Westmoreland is doing well after having surgery to repair a broken collarbone he suffered making a dramatic catch in the outfield for the Single-A Lowell Spinners last August.

The Portsmouth native is almost completely recovered from his surgery in September, when he had a plate and screws inserted into his clavicle to repair the damage.

“He’s doing great,” said Red Sox director of player development Mike Hazen. “He has no pain and his range of motion is back 100 percent. Everything went really well and we have no concerns right now physically.”

Westmoreland will be able to begin the organization’s strength-training program on time right after Thanksgiving in Fort Myers, Fla. He was selected by the Sox as the 172nd overall pick in the 2008 draft and already is showing a lot of promise.

He hit .296 with 15 doubles, 3 triples, 7 homers, 35 RBI, 19 stolen bases and a .401 on-base percentage in 60 games for the Spinners last summer before the injury.

jmcdonal@projo.com