SAN DIEGO — When Pawtucket Red Sox manager Ron Johnson summoned David Murphy into his office in Indianapolis Thursday night, Murphy had no idea what was in the offing.

As it turned out, Johnson was delivering good news: Murphy was headed here to join the Red Sox, filling the roster spot vacated by injured pitcher Curt Schilling.

But Murphy’s uncertainty reflected his current standing in the Red Sox’ organization. A first-round pick in the 2003 draft, Murphy is 25 and has seemingly fallen off the Red Sox’ radar despite yesterday’s promotion.

If the Sox had as much faith in Murphy as they once did, it’s unlikely they would have signed J.D. Drew to a five-year contract last winter. And the outfielder most talked about in Pawtucket these days isn’t Murphy, but another No. 1 college player, Jacoby Ellsbury.

Murphy doesn’t disagree that he may have dipped some on the Red Sox’ depth chart and agrees that the Red Sox would probably like to see him show more power. Before he was promoted, Murphy had just five homers in 69 games while with Pawtucket.

“That would definitely be beneficial to me, to have them see me drive the ball more consistently,” acknowledged Murphy. “`I don’t know exactly what they’re looking for, but I think that would help.”

To aid him in that goal, Murphy undertook an offseason strength and conditioning program in his native Texas. It helped him build up his upper body and maintain his strength halfway through the Triple-A season, but it hasn’t resulted in more power.

“My body has held up, thanks to all the work,” he said. “I’ve never felt this strong this deep into the season. Health-wise, it’s the best I’ve felt. But as far as driving the ball, that’s almost a completely separate skill. When it comes to that, I’ve always been streaky. It seems I go a few weeks and hit a lot of singles, then I start hitting the ball in the gaps. Sometimes, it’s hard to figure.”

Murphy also understands that he likely won’t stay with the Sox for long. By Tuesday, the Sox need to call up someone from the minors to take Schilling’s turn, and Murphy will almost certainly be returned to Pawtucket to make room.

But while he’s here, he finds himself more comfortable, thanks to a stint last September and a long stay in major- league camp in spring training. No longer are the veteran players strangers to the former Rice standout.

“That definitely helps,” he said. “I mean, I’m not going to lie. I was a little nervous this morning. But once I got here and was in the environment, I felt comfortable right away.”

Late last season, with the Red Sox reeling from injuries and out of contention, Murphy got into 20 games and got all the firsts out of the way — first hit, first road trip, first homer.

It’s likely he’ll get another call-up in September when rosters expand, but by then, Ellsbury will probably be here, too, eclipsing Murphy.

“He’s a kid I had never gotten to see play,” said Murphy of his teammate. “But he’s the real deal. I can see why he’s regarded so highly. Our style of games are completely different. He’s more of a leadoff-speed guy. I can run, but to get to the big leagues (and stay), I’m going to have hit some doubles, hit some balls to the gap. Our contributions are going to be a little different.”

Murphy’s name has been mentioned frequently in trade talks, and it’s possible, given Ellsbury’s emergence, that the Sox could include him in a deadline deal for some bullpen help or to fill another need.

With Ellsbury on the way, Drew under contract and Manny Ramirez in left for at least one more season, a fresh start elsewhere might be the best thing for Murphy.

“At this point, whatever happens is going to be whatever happens,” he said. “I’m not really going to worry about it, because then it becomes more of a problem for me. All I can do is go out and do my best.”

For however long he’s here.

smcadam@projo.com