Little did mercurial Portland Sea Dogs outfielder Jacoby Ellsbury know how “lucky” that lucky Red Sox cap he bought two years ago would be.

The junior-to-be at Oregon State University was playing in the Cape Cod League in the summer of 2004 when he was one of a handful of players invited to attend a Boston Red Sox game and take batting practice at Fenway Park.

“That was the first time I saw Fenway and Red Sox Nation. It was unbelievable,” the former Oregon State University outfielder recalled. “I was so impressed I bought a Red Sox cap at the game.”

After following the magical 2004 Sox season that culminated with a dramatic comeback from an 0-3 deficit in the American League Championship Series and a 4-0 sweep in the World Series, Ellsbury figured there might be some magic in that hat.

“Before every one of my college games last year, I’d wear my lucky Sox hat,” said the 22-year-old.

There was probably more skill than luck involved in his production last year, but the cap certainly didn’t hurt as Ellsbury was named the 2005 PAC-10 co-player of the year after hitting .416 with six home runs, 17 doubles, 46 RBIs and 21 steals. He also had a perfect fielding percentage (1.000) with no errors in 117 chances.

The good times kept rolling after the regular season as Ellsbury led the Beavers to their first College World Series appearance since 1952 and was selected by Boston in the first round of the Major League Baseball amateur draft in June.

If Ellsbury moves up the Sox organizational ladder with anything close to the same kind of speed he shows on the basepaths and in the field, the 6-foot-1, 190 pound speedster could be back in Fenway taking batting practice for real as early as next season.

Ellsbury, who is half Native American (Colorado River Tribe, Navajo), is batting .316 with 10 RBIs, nine steals and two doubles in 25 games since his July 13 promotion from (high) Single A Wilmington (N.C.) to Double A Portland.

“He’s a very special player,” said Sea Dogs manager Todd Claus. “He’s in the top five of most exciting players I’ve had because he can impact the game on both sides of the ball.”

Claus isn’t alone in his admiration and assessment of Ellsbury, who swiped 56 bases in three seasons at OSU.

“I remember Theo Epstein came to the University of Washington to see me play one time,” said the Madras, Ore., native. “That day, I didn’t get a hit, but I walked and scored from first on a hit to center. I think I really made an impression with that because he mentioned that to me later after I signed.”

It must have been quite an impression. Three years after being drafted out of high school in the 23rd round by Tampa Bay, Ellsbury was drafted 23rd overall and offered a $1.4 million contract by Boston to sign.

Ellsbury continued to impress in spring training this year as he robbed a top Sox prospect of an extra-base hit with a sprinting, lunging stab of a line drive.

“I took a hit away from David Murphy when Curt Schilling was pitching and Curt gave me a couple of fist pumps on that one,” he said. “That was great.”

Claus sees Ellsbury as a “30-plus stolen base guy” in the majors who can also hit 10-15 home runs once he refines his baserunning and batting skills.

“He’s an excellent athlete and one of those quick-twitch muscle fiber guys that makes for an explosive runner,” Claus said. “He’s not just fast in terms of speed, but baseball fast with a great first step on the bases and makeup speed in the field if he misjudges a ball.

“You can just see he’s a gifted outfielder. He has that bounce on the field like a gazelle.”

Hey, wait a minute… A player in the notoriously slow-footed Red Sox organization described with words such as “explosive runner” and “gazelle?” This is different.

“Before I was drafted by the Red Sox, I really didn’t know that much about them, but in talking to people, they said they weren’t known for stealing a lot of bases,” Ellsbury said. “It’s nice coming to an organization that doesn’t necessarily use the run game and still have them give me the green light to steal and use my speed.”

Ex-major league infielder and current Lowell (Mass.) Spinners manager Luis Alicea recognized Ellsbury’s ability early on and gave him that green light. The result was 23 stolen bases in 35 games for low Single-A Lowell last season. He was caught stealing only twice.

In addition to a new league, new team and new pitching, Ellsbury is also adjusting to living on the opposite coast.

“I like both coasts. I’m half Native American and half white so I think I can adjust culturally to anything,” he said. “What I’m not used to is the humidity. I knew it was kind of muggy, but I didn’t have a clue what it was like. I thought 110 in Arizona was pretty hot, but it gets really hot here.”

Andrew Neff can be reached at 990-8205, 1-800-310-8600 or at aneff@bangordailynews.net