Now that right-hander Brock Huntzinger is in his fifth season in Boston’s farm system, the Red Sox hope he’s finally learned there’s a difference between being a thrower and a pitcher.

Commencing at Pendleton Heights (Ind.) High School and continuing through his first years with Boston, Huntzinger often was content with just blowing -– or trying to blow –- his fastball by batters.

That’s one reason why, in 2008, he served up 12 home runs in only six games with the Greenville Drive.

A 6-foot-3, 200-pounder, Huntzinger’s fastball has topped out at 95 but despite his record last season at High-A Salem, he appears to have grasped the concept that even if he throws 90, 91 or 92 and hits his spots, he’ll be much more effective.

In his first season at this level, Huntzinger was 7-8 with a 4.14 ERA in 25 starts replete with only 35 walks and 69 strikeouts in 134 2/3 innings pitched.

“He showed he has the ability to pitch to both sides of the plate,” said an American League scout. “If he continues to do that, it will be a huge plus for him.

“He also needs to stay down in the zone which, really, is something you can say about most pitchers especially young ones like this kid (Huntzinger turned 22 last July).”

So far this season, Huntzinger’s ability to “stay down in the zone” has produced mixed results.

In his first 11 starts with Portland, Huntziner was 3-5 with a bloated 6.85 ERA, 17 walks and 37 whiffs in 47 1/3 innings.

Huntzinger uses an over-the-top delivery which starts off slow and releases smoothly out of his hand. In truth, there’s very little wasted motion in his delivery. In a sense, his fastball is deceptively fast because of his smooth delivery.

Boston’s third-round pick in the 2007 draft, Huntzinger also uses a slider that tops out between 79 and 83, plus a changeup which was a pitch he never used until he signed with the Red Sox.

He displayed improvement with his changeup last season as the games kept flying off the calendar.

“One thing this kid must work on is pitching out of the stretch,” said the scout. “Sometimes when he’s in the stretch, he loses velocity off his fastball, whether he’s throwing a four-seamer or a two-seamer, and that can’t happen if you want to move up.”

Given the number of innings he’s pitched (he led Greenville with 125 in 2009), Huntzinger has shown durability –- although the Red Sox do tend to baby their prospects.

“One thing I’d like to see is his putting on a few more pounds, which could add something to his fastball as well as his stamina,” said the scout.