PAWTUCKET — The disappointment is evident on Chris Carter's face. He thought this was his year, his chance to show what he can do at the major-league level.

He made the team out of spring training but was sent down in favor of Jeff Bailey after only five ugly at-bats. It quickly became clear that Bailey was emergency Plan A, and Carter Plan B, when a 1B/OF spot needed to be filled.

Carter was fine with that. He thought that after Bailey, he was next in line to be called up.

On Monday, Bailey went on the disabled list. Carter expected to be on his way to Boston.

Instead, Carter was stunned to learn that he had been passed over in favor of Aaron Bates, who had only made the move from Double-A to Triple-A a month ago. Bates was hitting .182 with two home runs. Carter was hitting .274 with seven.

"I didn't expect that. It was unexpected. It caught me by surprise. It really did," Carter said. "I called my dad right away, because I knew he was going to be hurting, because he thought I'd get the call. I called him and said hey, this is what's going on, don't be surprised. Then I called my agent and my girlfriend and let them know."

Being passed over was the roughest moment in a disheartening year for Carter, one that has made him wonder where he stands within the Red Sox system. He said he was happy for Bates. But he is confused, because he thought he understood his place.

"I don't really know my position in the organization. All I know is I need to play well. That's the only thing I can control," Carter said.

Carter has mostly kept quiet about his disappointment. He knows he might have a chance to play regularly in the majors for a lesser team. But his goal has long been to earn a spot on the Boston Red Sox.

"There would probably be more opportunities for a not-so-good team, but I want to play for a championship team. I want to play for the Red Sox," Carter said.

That said, if he's not going to be called up, he has few options.

"It's such a tough situation, because I'd never ask for a trade right now. I really do want to be part of the Red Sox, I really do. I feel like this is the best organization in baseball. But you know what — things like that happen. I got traded to here from another team. So that's always a possibility," Carter said.

Carter came to Boston from the Diamondbacks in a 2007 trade for Wily Mo Pena. He mashed at an All-Star level for the PawSox last year, hitting .300 with 24 home runs and 81 RBI in 470 at-bats. His defense is mediocre, but he entered spring training this season competing with Brad Wilkerson, Bailey, and Paul McAnulty for the last spot on the roster. He won.

His tenure was short-lived. Three weeks into the season, Carter was sent down when injuries made a backup centerfielder more valuable than a backup first baseman/leftfielder.

In May, Carter thought he had another chance. He was flown out to the West Coast during a series in Anaheim, when an injury to Kevin Youkilis left Boston with little first-base depth behind Bailey. He spent a day in a hotel room waiting for a phone call that he would be activated. It never came, but he left with the understanding that the next time there was a need, he'd get the call.

As soon as he heard about Bailey's ankle sprain, Carter expected to be heading up to Boston, despite the fact that Bailey is a right-handed bat and Carter hits lefty.

"I thought if Bailey got hurt, they might either call me up, or call Velazquez up like they did that last time," Carter said.

When Bates was called up, Carter had a tough time controlling his emotions. The righty-lefty explanations didn't assuage his feelings. Hitting coach Russ Morman had to talk him .

"There was an hour where I could have gone either way," Carter recalled. "I didn't know what to do. Russ pulled me aside and talked to me. He really made it so I went right into the cage immediately, started taking ground balls. I started doing the things that I should be doing. And I'm really thankful for Russ."

Carter, nearly 27, went 5-for-8 in a doubleheader that day, and 2-for-3 the next evening.

Nearly 27 now, Carter frets that his moment is passing him by.

"My clock's ticking. Physically. Contractually. It's coming down, this year and next. But I do believe in myself," Carter said.

Realizing that he's not necessarily next in line has been unsettling.

"It's tricky, because I don't know, so much, who I'm competing against, and I can always lose. There's always someone that can be a better fielder than me, that can hit for more power. Who's younger. There's so many more factors now, where I can lose this battle," Carter said.

It has made him feel, more than ever, that he must seize the moment now, and hit the ball so well that either the Red Sox are compelled to bring him up, or another team is enticed enough to make a suitable offer for him.

He has worked on his defense, and now plays right field regularly in addition to left and first.

"I think someone will notice. I really do. And I think the Red Sox will notice," Carter said.

"I know it'll ultimately work out," he said. "I just don't know how."

dbarbari@projo.com