PAWTUCKET — Jonathan Papelbon. Jon Lester. Manny Delcarmen. Craig Hansen. Clay Buchholz. Justin Masterson.

The stream of young, athletic pitchers with good stuff has been steadily flowing through the Boston Red Sox’ organization, fueling the big-league team for the important arms race in the major leagues.

Now it’s Michael Bowden’s turn.

Bowden, a 21-year-old right-hander, is the organization’s latest pitching phenom. He has been promoted from Double-A Portland and will make his Triple-A debut tonight for Pawtucket in Columbus.

The 6-foot-3, 215-pounder went 9-4 with a 2.33 earned-run average in 19 starts for the Sea Dogs, ranking second in the Eastern League in E.R.A. and strikeouts (101 in 104 1/3 innings). Bowden spent the second half of the 2007 season in Portland, compiling an 8-6 record and a 4.28 E.R.A.. He had 82 strikeouts in 96 2/3 innings over 19 starts.

“He has done everything he could do in Portland. Basically, he was there for a full year. I’m not a ‘numbers’ guy, but his numbers were impressive and he worked hard to improve every part of his game. He should be here,” said Ralph Treuel, the organization’s minor-league pitching coordinator, after Bowden had thrown about 13 pitches in the bullpen at McCoy Stadium yesterday in preparation for his start tonight.

Bowden’s repertoire features a power fastball and, according to Treuel, his secondary pitches, the changeup and the curveball, have shown steady improvement. His mound presence also has been impressive, all of which puts him on the same fast track that most recently has sent Buchholz and Masterson to the big leagues with relatively little Triple-A experience.

“He’s a bulldog on the mound,” said Treuel. “He comes after you.”

Not surprisingly, Bowden is looking forward to taking the next step in his organizational development.

“I’m excited, it should be fun,” said Bowden of tonight’s assignment.

He doesn’t lack for confidence, either, though he does not come off at all as cocky. Nor does he seem like a youngster who will be adversely affected by the weight of expectations.

“I’m just going to try to continue what I was doing in Double A. If I stick with the same approach that I had in Double A, I don’t see why I wouldn’t have success here or in the big leagues, for that matter,” said Bowden yesterday, sweat dripping off him after he completed his bullpen workout on the steamy afternoon.

“I’m not going to put pressure on myself. There are some great pitchers up there in Boston, so there is no pressure on me. They’re taking care of business up there. I have high expectations for myself,” said Bowden, a sandwich pick (47th overall) between the first and second rounds of the 2005 draft after starring at Waubonise Valley (Ill.) High School.

While the Columbus Clippers will be getting their first look at Bowden tonight, the same is basically true for Pawtucket manager Ron Johnson. He hasn’t seen a lot of Bowden on the mound, but he has liked what he did see.

“What excites me about him is the unknown,” said Johnson yesterday before Pawtucket’s 8-4 loss before a crowd of 10,315 in the finale of a four-game series with the Toledo Mud Hens.

“I saw him in spring training for one inning and what caught my attention was his tenacity,” said Johnson. “I had heard he was a bulldog pitcher and I watched him, and he really attacked the hitters. Now, that was just one inning on a back field in spring training, but for me, that was impressive.”

The ascension of Bowden, on the heels of the other young pitchers who have moved swiftly through the minor-league system and have made solid contributions already in Boston, is a feather in the cap for the organization’s scouting department, headed by Jason McLeod, the director of amateur scouting.

“I’m a big Jason McLeod fan,” said Johnson. “Seeing the amount of quality talented individuals rolling through the system, it excites me to be able to see another one.”

In keeping with the organization’s philosophy, Bowden will be eased into his new level of competition.

“What we’re doing with Michael is to make sure things don’t get too hyped up,” said Johnson. “He’s still just a young man. This is going to be his first Triple-A start. I don’t feel we have to put monster expectations on him. We’ll give him the ball, have him throw 75 pitches or so and go from there.”

Where he’ll go from there, if all goes well, is Boston. And if recent history is any indication, given the young pitchers who have preceded Bowden to Pawtucket and then to Boston, that trip up Route 95 may not be too far in the distance if he continues to progress as expected.

“My goal all year has been to get to Boston by the end of the year,” said Bowden. “It’s still attainable, so we’ll see.”

skrasner@projo.com