By BRENDAN MCGAIR

Sports writer

Trades happen. Injuries can come at a moment’s notice. If you’re the parent club, who are you going to call?
None other your friendly neighborhood Triple-A affiliate.

The function of the Pawtucket Red Sox isn’t any different from the rest of their Class AAA brethren. The players making up the PawSox’ roster are at the beck and call of the major league team they serve.
Over the last few seasons, PawSox fans have been privileged to watch the likes of Jon Lester, Manny Delcarmen, Dustin Pedroia, Kevin Youkilis, Clay Buchholz, Jacoby Ellsbury blaze through town. All have “graduated” and gone on to form a nucleus that could potentially make the Red Sox a contender for years to come.
Yet for every highly touted prospect, there are those minor leaguers who boast MLB credentials who can just as easily be depended upon. Guys who fit that description who have suited up for Pawtucket the past couple years include Joe McEwing, Michael Tucker, Junior Spivey and Royce Clayton.
Perhaps the best way to sum up a Triple-A team is that it’s always constantly changing. The PawSox club that breaks camp in Fort Myers will barely resemble the one left standing by Labor Day (Sept. 1).
In science, this metamorphosis is called a butterfly shedding its cocoon. In baseball, it’s simply business per usual.
STARTING PITCHERS
The front end of rotation features familiar faces in right-handers Devern Hansack and David Pauley. While neither falls in the Lester or Buchholz category, both could be viewed upon as short term fixes.
Hansack, a native of Nicaragua, might be 29, but last season was his first at Triple-A. He finished near the top in the International League in strikeouts (131) and ERA (3.61).
Last season was also Pauley’s first full one in Pawtucket, going 6-6 with an ERA of 4.33 in 27 games.
There are more familiar faces. Knuckleballer Charlie Zink, an undrafted free agent on the recommendation of Luis Tiant, has logged time with the PawSox in each of the last three seasons. Last season saw the right-hander undergo a rough patch (5.89 ERA in 47 frames).
The lone expected left-hander is Michael Tejera. Tejera actually pitched for Double-A Portland in ’99, back when it was a Florida affiliate. Most recently the 31-year-old pitched for Indianapolis (8-5, 3.90 ERA).
Rounding out the rotation is rehabbing Bartolo Colon, brought in as an insurance policy should any leaks surface in Boston’s rotation. The 2005 American League Cy Young winner turns 35 in May and has a clause in which he can opt out of his minor-league deal on May 1 if he’s not on the big league roster.
It’s not unreasonable to think either Justin Masterson (Boston’s No. 4 prospect according to Baseball America) or Michael Bowden (No. 7) will land in Pawtucket sometime this season. Both will start the season in Portland, but should hopefully move up sometime around the All-Star break.
RELIEF PITCHERS
If Craig Hansen’s slider is, indeed, back, then the pieces that Red Sox fans have been waiting patiently to come along might finally fall into their proper place. Armed with a blazing fastball, Hansen can either fill the void as a late-inning option or as manager Ron Johnson’s closer.   
After realizing his days as a starter are a numbered, Abe Alvarez is going to try his luck as a left-handed specialist. He will likely be in to face a batter or two, for trouble usually brews the longer he left out on the mound.
Listed at 6-foot-4, 240 pounds, Lincoln Holdzkom is an imposing figure. Armed with a low 90s fastball, the biggest obstacle Holdzkom must overcome control issues (14 walks in 17 innings with Pawtucket last season).
After dominating the lower minors, Edgar Martinez has struggled against advanced hitters. Last season saw the right-hander post a 5.16 ERA allow 11 home runs in 68 innings.
The newcomers include Jon Switzer and Dan Kolb. Switzer split time last year with Tampa Bay and Durham. Like Alvarez, Switzer could also be one batter or two candidate.
Kolb was an All-Star four years ago, saving 39 games for Milwaukee, but has struggled to remain that form since. Most recently the 33-year-old Kolb was in the Pittsburgh organization.

CATCHERS
If pitching is at a premium, so too are catchers.
Sooner or later the Red Sox will have to inject youth into a position that features thirtysomethings Jason Varitek and Kevin Cash. The problem is that there’s not much in terms of depth lurking down on the farm.
After struggling to break .200 for much of the first half, George Kottaras rebounded in the second half to finish at .241 in his first season of Triple-A ball. His glove however, is a different story. Kottaras does have a strong arm, but at times struggled throwing out runners.
Kottaras, 24, will share the duties with Dusty Brown (25). Brown got into eight games with the PawSox last season after spending the bulk of the year in Portland. Brown contains a strong arm and is regarded as a streaky hitter.

INFIELD
Shortstop Jed Lowrie made a smooth transition to Class AAA pitching, batting .300 in 40 games upon his promotion in late July. The switch hitter wound up as Boston’s minor league offensive player of the year, slugging 13 home runs and 70 home runs between Pawtucket and Boston.
Drafted as a second baseman, Lowrie has adjusted in moving to short. Though his name appeared in numerous trade rumors, Lowrie should be one of the first infielders to get the call should the need arise in Boston.
Jeff Bailey will likely see time at DH, though he can play first base and the outfield. Back for his fourth tour with Pawtucket, Bailey, a solid clubhouse presence, can be counted on for 10-15 home runs and over 100 strikeouts.
Acquired in the Wily Mo Pena deal, Chris Carter boats some pop (has slugged 19 home runs in each of the last two seasons). He should see time at first.
Joe Thurston is a player who can wear multiple gloves, but likely he’ll serve as Pawtucket’s second base. Thurston was with Ottawa last year (.300 in 129 games). In addition to playing second, Thurston can also fill in at shortstop and the outfield.
Keith Ginter and Chad Spann should split time at third base. Ginter played with Buffalo last season (15 home runs, 62 RBIs) while Spann struggled with Pawtucket (.223 average).
Iggy Suarez and Gil Velazquez are expected to add depth thanks to their ability to play multiple positions.

OUTFIELD
With every position in Boston virtually sown up, a player must seek other avenues. For Brandon Moss, that means learning how to play a different position. Though Moss, an IL All-Star last season, will be primarily in right field, he will some action at first base.
Moss started learning the ways of a first baseman at the tail end of last season before playing almost exclusively there during Winter League play. Moss matched his career best with 16 home runs last season and has the ability to hit to all fields.
PawSox fans should expect to see numerous highlight reel catches from centerfielder Jonathan Van Every, known for his ability to take away hits destined for the gaps. A 28-year-old who spent his first eight professional seasons in the Cleveland Indians’ organization, Van Every boasts a solid stick (12 home runs in two stops last year).
Rich Thompson should start in left field. A career minor leaguer, Thompson does have speed which could make him an asset towards the top of the lineup. Like many of the PawSox outfielders, Bryan Pritz can play all three positions.