Boston rookie Brandon Moss, catching a fly ball hit by the Orioles’ Brian Roberts on Sept. 1, started last night in left field.

The Providence Journal / Bob Breidenbach

BOSTON — As Brandon Moss stood in the Red Sox clubhouse yesterday with a pack of reporters circled around him, it was hard not to notice the wide smile on his face.

When Moss reported for work a half-hour earlier, he saw his name penciled in as the starter in left field. For a 23-year-old from the tiny town of Loganville, Ga., stepping into the lineup for the best team in baseball is about as cool as it gets.

He was so excited to play last night that as soon as he finished lacing his spikes, he realized he’d forgotten something. Like pulling on his pants. Reminded that his uniform wasn’t quite complete, Moss laughed at himself and finished the job.

“It makes you feel good. That’s what you want as a baseball player,” he said. “You want them to have confidence in you and the confidence to throw you out there in a pennant race.”

Moss is just the latest in a wave of young players who’ve shined in the Red Sox farm system and begun helping out in Boston. He’s hoping to join Rookie of the Year candidate Dustin Pedroia, impressive outfielder Jacoby Ellsbury and pitchers Jon Lester, Manny Delcarmen and Clay Buchholz, who’ve all chipped in over the last few months.

Moss was a September call-up after a strong season in Pawtucket where he earned the PawSox MVP award. He hit .282 with 16 homers and 78 RBI and led the International League with 41 doubles, two shy of the Pawtucket team record. The Sox planned on Moss getting his feet wet this month, hanging with the stars and taking lots of balls at first base to learn a new position.

But when Manny Ramirez tweaked his oblique muscle in the last week of August in New York, a chance to take a few turns in the outfield materialized. Ellsbury has filled the role superbly, hitting .400 with 3 homers and 9 RBI in the 11 games he’s played in. A minor wrist injury kept Ellsbury on the bench last night against the Devil Rays and opened the door for Moss to get his third start in left field. He stroked his fourth major-league hit (and first double) off the Wall in the second inning and ran into no problems in a position known for its hazardous duty.

“It’s a little difficult because you never know where the ball’s going to bounce off (the Wall) but at the same time you don’t have to worry about going back on balls because you turn around and it’s right there. It’s like any other park, you just have to get used to it,” he said. “The two corner outfield positions are both very unique here. You have no idea where (the ball) is going to go. When it gets in that corner in right and off the Wall in left, it can do anything.”

Moss, Ellsbury and another PawSox alumn, Devern Hansack, dress in adjoining lockers smack in the middle of the Red Sox clubhouse. It’s the least desirable spot in the crowded room, but one September call-ups have called home for years now.

“I didn’t know what to think but I hoped we would be up here and enjoying this exact experience. The team’s in first place and trying to win a pennant. That’s what I had hoped for,” Moss said.

This is actually Moss’ second trip to the Show. He was an emergency call-up from Aug. 6-8 when the Sox were an outfielder short for a series in Anaheim. That was an anxious test for the youngster. Now it’s all about having fun.

“That helped a lot. In Anaheim, I was so nervous. I didn’t know what to expect. Just getting that initial feeling out of the way was huge,” he said. “Coming back in September, it was a lot less. That first experience is a little intimidating but after that it’s just another ball game.”

It won’t be another ball game this weekend when Moss takes part in his first Red Sox-Yankee series. He’s watched the rivalry on TV and witnessed the intensity of the fans while in Pawtucket but matching up with the Bronx Bombers with the A.L. East race still up for grabs is a thrill.

“It’s going to be exciting. It’s going to be big,” he said. “I’m excited and my family is coming up for it and I’m excited to see them. Just because it’s your first time being in an actual Yankee series I’m a little fired up about it and excited by it but at the same time, it is one game at a time. You can’t look too far ahead.”

kmcnamar@projo.com