PORTLAND, Maine — It hasn’t taken speedy center fielder Jackie Bradley Jr. very long to move up the ladder in the Boston Red Sox organization.

Last year, he was leading the University of South Carolina to its second straight College World Series title.

After being drafted by the Red Sox in the first round and signing with them for $1.1 million, he got a 10-game taste of minor league baseball last summer.

Then, after leading all Red Sox minor leaguers in hitting (.359) for Salem in the high Class A Carolina League, he was called up to the Portland Sea Dogs, where he has been on a tear.

Entering Monday’s doubleheader against Trenton, the Sea Dogs’ leadoff man was hitting .353 through his first 13 games for the Sea Dogs. He had 18 hits, including four doubles and a triple, and had scored 10 runs. He also drove in six and had a .433 on-base percentage.

“He’s one of those guys who, when you try to figure out who has the best chance to play in the big leagues, he’s at the top of your list,” said Sea Dogs president and general manager Charlie Eshbach. “He is fun to watch. He’s something special. He’s 100 percent involved in every game. He covers all kinds of ground in the outfield. He’s really quick. He scored from first on a double to left.”

Assistant GM Chris Cameron concurred.

“He is certainly one of the most talented and exciting players in all of minor league baseball,” said Cameron. “He’s a game-changer.”

Bradley, who turned 22 in April, said he hasn’t been surprised by his success.

But he doesn’t dwell on it.

“I’m not surprised by anything. I just take it one day at a time and whatever happens, happens,” said Bradley. “Things have been going all right but I’m never satisfied. There’s always room for improvement. I’m constantly trying to get better every single day. I’m just happy that I’m healthy.”

His wrist is healthy after the surgery which cost him a healthy chunk of his junior year at South Carolina.

He returned to the lineup to help the Gamecocks claim their second straight title. He had been the CWS’ Most Outstanding Player in 2010.

“It was great. To be able to play against some of the best college baseball teams in the country and to win two championships in a row is big,” said Bradley. “They were the first and second national championships in school history and that was big for our fans.”

He said his 10-game stint in Class A Lowell and Greenville “got my feet wet in the pro baseball lifestyle.”

He worked out hard in the offseason and played in the Fall Instructional League.

Bradley is a student of the game. He reads pitchers and tries to apply the right approach to each at-bat.

“You’ve got to know every pitcher and apply a different approach. Against certain guys who fill up the strike zone, I’ll be more aggressive. With other pitchers [whose control isn’t as good], I’ll work the count.”

His primary focus right now is getting a “better first step.

“That will help me defensively and to steal bases,” said Bradley.

He has enjoyed Portland although he hasn’t been there long.

“So far, so good,” said Bradley.