Just when you thought the Red Sox’ minor league system’s well had run dry of top pitching prospects, you turn around and notice Justin Masterson blazing his own trail.

Justin Masterson may be the next big Sox pitcher to make waves.

Like Jonathan Papelbon, Manny Delcarmen and, most recently, Clay Buchholz before him, Masterson is turning the heads and radar guns of scouts who have been almost permanently camped in Portland for the past year.

The 2006 second-round pick out of San Diego State has built up a perfect 4-0 record with a nearly unthinkable 1.09 ERA for the Sea Dogs, mowing down batters at a shocking 32-5 pace (32 K’s, 5 BB’s).

So, how is the rangy righty doing it? Well, his size certainly doesn’t hurt. Masterson is listed conservatively at 6-6 and 245 pounds, and he uses his considerable physical assets to help him rear back for a full range of speed on his sinker, which is his clear A+, out pitch. His best sinkers have varied between 86 and 94 miles-per-hour, a wide enough range to keep any and all batters off balance.

Not to be outdone, Masterson’s slider sits in the low 80s but has phenomenal action, which is good enough to help him get out of jams. When combined with what has been described as a rapidly improving change-up, Masterson’s arsenal has made him a rapidly rising prospect for trade discussions and future projections.

Though Masterson is Oregon born and bred, he’s no stranger to New England. In 2005 he dominated the Cape Cod league. Now, he’s spent the past three summers in the region, finishing out a short 2006 session with A Lowell after a late signing.

So, will Masterston make a move to Pawtucket, or even Boston, in the not-too distant future? And will he pitch from the start or break through as a reliever? Those questions are clearly too far away, as Masterson himself as acknowledged in an interview with soxprospects.com.

In the meantime, it’s pretty clear that he’s figured out how to get things done in Portland. Here’s betting that won’t subside any time soon. But don’t just take our word for it. Here’s Amalie Benjamin’s piece in today’s Globe, which also leads with Masterson. Got to love it when the people who travel with the team agree with which prospect is turning the most heads.

HIT AND RUN
The Thursday signing of former big leaguer Brady Clark to a minor-league deal was a direct reaction to the minor groin injury suffered four days ago by top prospect Jacoby Ellsbury. There’s no official report on how much time the center fielder of the future might miss, but early expectations are that he still could be on track to earn a call-up to the big club come September. …
Clay Buchholz is set to start again for Pawtucket tonight, and it’ll be interesting to see how he responds from his first outing, where he gave up three runs, one on a monster home run out of McCoy Stadium. He’ll be facing the Toledo Mud Hens, just as Curt Schilling did last night. …
Michael Bowden is another arm who keeps coming up in prospective Sox trade talks, though most big fish (read: the Rangers in talks for Mark Teixeira) have requested two prospects from a list that includes Jon Lester, Ellsbury and Buchholz. Naturally, Theo Epstein and the Sox brass have said they won’t part with any of those names, which is bringing on much of the current stalemate in deals. …
Rapidly rising shortstop prospect Jed Lowrie was promoted from Portland to Pawtucket, a move which wasn’t entirely a shock (he was hitting .297 for the Sea Dogs). But, the shift that was surprising was the Rhode Island move-up of right-handed pitcher Lincoln Holdzom. PawSox infielder Zach Borowiak and pitcher Barry Hertzler took the bus ride up to Maine to make room for the new duo. …
According to Benjamin’s weekly notebook, Class A Lowell center fielder Ryan Kalish, who was hitting a preposterous .368, will miss the rest of the season with a broken hamate bone in his right hand. You’ll recall that Big Papi and Wily Coyote both had that bone removed from their right hands after being similarly struck by pitches in recent years. Doctors haven’t determined if Kalish will have to lose the bone altogether, or whether he can hold off and let it heal on it’s own. Here’s betting he does whatever the tell him will least affect his sweet swing.

– Cameron Smith