BOSTON — The decision was made so suddenly yesterday afternoon that Jacoby Ellsbury didn’t even have a nameplate on his locker stall in the Red Sox clubhouse.

Because Red Sox reliever Joel Pineiro was placed on the 15-day disabled list yesterday with a sprained right ankle and center fielder Coco Crisp is unable to play with a bruised left thumb, Boston general manager Theo Epstein decided it was time to summon Ellsbury from Triple-A Pawtucket.

There has been much anticipation over the 23-year-old outfielder’s arrival in Boston. Boston’s first pick, 23rd overall, in baseball’s 2005 amateur draft, Ellsbury has been successful at every level he’s played at.

One American League scout recently described Ellsbury as an everyday big-league player, who should have success as a leadoff hitter and be able to handle center field with no problem.

“He’s still developing,” said Boston manager Terry Francona. “No one is saying he’s a finished product. He’s hitting at the bottom of the order and we’re not asking him to jump-start our offense, but he should catch a lot of balls in center field. (Allard Baird, the Red Sox’ assistant to the general manager) said Ellsbury has survival skills and there’s something to be said for that.”

Baird means the kid is a competitor and handles adversity as well as a seasoned veteran. Ellsbury prides himself with being even-keeled and not letting things bother him.

“For a young kid, that’s a compliment,” said Francona. “He has the ability to impact our ballgames.”

Crisp, despite his recent string of success prior to his injury, has been a disappointment. Crisp hurt his thumb last Wednesday when he dived trying to make a catch. Because the injury is worse than first thought, Francona said with the All-Star break coming up, the club could go with 11 pitchers. So it was decided to bring Ellsbury to take advantage of his stellar defense. The manager said Crisp’s injury is not bad enough to warrant a trip to the disabled list.

Yesterday was clearly not about the past, but what the future holds for the Red Sox and Ellsbury.

Ellsbury has been compared to a young Johnny Damon. But some who have seen both during their developmental stages say Ellsbury is better. He’s quicker in the field and on the bases and has a stronger arm.

After participating in big-league camp this spring, Ellsbury was assigned to Double-A Portland but was promoted to Pawtucket on May 4. He combined to hit .323 with 29 stolen bases in 67 games for the Sea Dogs and PawSox this season.

“It’s always key to get off to a fast start because it makes the season easier,” he said. “I’m just going to do the little things that got me here. I’m not going to do anything special. I’m just going to go out there and play my game.”

Former Red Sox outfielder and base-stealing wizard Tommy Harper has spent time working with Ellsbury the last two seasons. Harper, who still holds the single-season mark for stolen bases in a season, with 54 in 1973 for the Red Sox, recently said Ellsbury will be the one to break that record.

Harper wasn’t planning on staying for the Red Sox’ game last night, but when he arrived at the park early in the afternoon and saw Ellsbury standing in the clubhouse, there was no way he would miss the rookie’s debut.

“It couldn’t have happened to a nicer kid,” said Harper. “He’s going to do all right.”

Because Ellsbury carries the title of phenom along with him, Harper said he’s hoping the pressure from the media and the fans won’t have an effect on his game. There shouldn’t be any problems with outside distractions, however, because Ellsbury acts as a true professional on and off the field.

“He wasn’t the savior in Pawtucket and he won’t be the savior here,” said Harper. “He’s just a player who can fit in and do a good job. He just needs to play his games.”

One of the most impressive things about Ellsbury is his willingness to learn and take constructive criticism. In Pawtucket, he was consistently working with Harper and PawSox veteran players such as Michael Tucker and Joe McEwing.

Ellsbury was told by Pawtucket manager Ron Johnson about his promotion around 2 p.m. yesterday as the PawSox were preparing for a youth clinic at McCoy Stadium. The youngster immediately packed his bags and headed north on Route 95. He admitted he was nervous during the drive, but once he got into the clubhouse he was all business, and that was obvious by his demeanor.

“I’ve worked really hard and this has been a life-long goal for me,” he said.

The jitters were obvious. But so was the talent.

Some day, Ellsbury will look back at his major-league debut and remember the first putout he made — a Sammy Sosa fly ball to left-center field. In Ellsbury’s first at-bat, the ball never left the batter’s box after his checked swing, but it was fair and he was tagged out by Rangers catcher Gerald Laird.

Ellsbury’s first major-league hit was a hard grounder to the left side of the infield that he legged out. As is the tradition, the ball was collected for his trophy case, but not before teammate Kevin Youkilis pretended to throw the ball into the stands.

It was a good day — one of many, in all likelihood, for Ellsbury in the majors.

jmcdonal@projo.com