The 2012 season has been, by and large, one of disappointment thus far for the Red Sox. Even as the team once again has popped its head above .500, it has spent most of the season enduring mediocrity, suggesting more questions than answers.

But in defiance of that prevailing sentiment, there has been one player who has emerged above all others with a performance that has the chance to transform what the franchise does for seasons to come.

After a 2011 season that was interrupted by one injury after another, there were no real expectations for left-hander Felix Doubront entering spring training. While the 24-year-old was thrown into the mix to compete for a spot in the Red Sox rotation, there was nothing to suggest definitively whether he would end up in the rotation, the bullpen or, perhaps, with another team, given that he was out of options.

But Doubront -- who is scheduled to start Wednesday night against the Marlins -- separated himself from the competition in spring training to earn a spot in the rotation, and since the curtain lifted on the regular season, he hasn’t turned back. He is 7-3 with a 4.17 ERA, ranking second on the team in wins and ERA. He has shown the best stuff on the staff, a four-pitch mix that has yielded 9.9 strikeouts per nine innings (second in the American League).

“It’s big,” Red Sox general manager Ben Cherington said of Doubront’s breakthrough in the rotation. “We looked at potential solutions after the season last year. He was a guy we weren’t talking about as much but were hoping he would be part of a solution and challenged him at the beginning of the offseason to put himself in a position to do that. He did.

“He hasn’t done it for a year. He’s done it for three months,” Cherington cautioned. “But so far, so good.”

If Doubront sustains that performance going forward, the significance for the Red Sox will be monumental. The left-hander represents what his Red Sox need, and a departure from what they have been.

In recent years, the Sox’ attempts to pay dearly for starting pitching have led to repeatedly poor yields. Daisuke Matsuzaka is trying to salvage the final months of a six-year tenure in Boston for which the team paid $103 million ($52 million over six years in salary and a $51.11 million posting fee). John Lackey, in the third year of his five-year, $82.5 million deal, is working his way back from Tommy John surgery that will cost him the 2012 season.

Josh Beckett has been mostly very effective for the Red Sox under the first 1½ seasons of his current four-year, $68 million extension. But the 32-year-old is currently on the disabled list due to shoulder inflammation. In a year when he has dealt with thumb, lat and shoulder issues, it would be hard for the Sox not to fret about the 32-year-old’s ability to remain effective and healthy over the remaining life of his contract.

The roughly $42 million wrapped up in those three pitchers this year (as calculated by average annual value) has meant everything in shaping the 2012 Red Sox. The long-term commitments -- to pitchers who, in a best-case scenario for the Red Sox, will supply roughly 1½ seasons worth of starts -- choked the team’s offseason roster flexibility and left the team with no option but to buy low at the back end of the rotation.

Thus, the team needed someone like Doubront to step forward and assert himself.

“We’re just trying to put the best team out there that we can with the resources we have,” Cherington said. “We have big commitments to starting pitching. You can’t have a full rotation of those guys. I think [the offseason blueprint was] just getting a balance rather than a shift [away from big-money free agents].”

Still, the team is unlikely to dive into the deep end of the free agent pitching pool again anytime soon. The team is mindful of the risks of spending huge sums on pitchers at an age when their health represents a growing concern, when success becomes more fragile because of the accumulated wear and tear on shoulders and elbows over a lifetime of pitches thrown.

And so, even with a tantalizing option such as free agent-to-be Cole Hamels on the horizon this offseason, the Red Sox are unlikely to pursue the left-hander aggressively.

“That’s not the way to build a team,” noted one team official, speaking of high-priced free agent pitching rather than Hamels specifically.

The Red Sox want a more homegrown rather than mercenary pitching staff. Doubront represents a step in that direction, someone who will not be arbitration eligible until at least after the 2013 season and possibly the 2014 campaign, and who will remain under team control through 2017.

His emergence will not preclude the Sox from exploring the starting pitching trade market this summer. Red Sox officials still consider their team capable of competing for a postseason spot, and as of now, they’re exploring the trade market accordingly.

However, because Doubront appears capable of being in the rotation for the longer term, the Sox can take a flexible approach to the trade market. The team does not feel that it needs to address its 2013 rotation at this trade deadline, with Beckett, Jon Lester, Clay Buchholz, Doubront and Lackey (about whom the team is mildly optimistic, given that he has been effective when healthy in his career) all under team control through at least 2014.

Doubront is young, cheap and left-handed and has shown the potential to be an above-average pitcher capable of holding his own in the American League East. If he can sustain the performance, he represents the type of pitcher around whom good rosters can be built, someone in the mold of Jon Lester and Clay Buchholz.

A couple of years ago, it was not clear that such an outcome would be possible. In each of the last two offseasons, Doubront’s name circulated as possible trade bait, given that there was no clear path for him into the Red Sox rotation.

“I heard about it. It’s a business. It was sad, because that many years with this team and then to get traded, that would make me feel sad,” Doubront said of the rumors that the team with whom he signed in 2004 might deal him. “But I understand that this is a business and they can do whatever they want. So I wasn’t paying attention too much to that.”

Now, though Doubront’s performance this year means that his trade stock is soaring, it is difficult to fathom the Red Sox considering a move involving him. He represents a commodity that is too valuable for the Sox to unload. Instead, at 24, he has become a potential building block for a franchise in need of infusing young, inexpensive talent into the roster at key positions.

Doubront is mindful that he has reached the point of liftoff in his career.

“That’s what I’m working for -- to stay with this team for a long time. I’m working for it,” Doubront said.  “I can do it. For me, I just want to be here in the big leagues for a long time, for the future. That’s my big goal.

“Coming from Venezuela, it’s amazing. All that work, when I look back, everything was worth it. What I want is here.”

And just as Doubront’s goals of establishing himself as a big leaguer are now almost within reach, so, too, are the Sox’ goals of bolstering their rotation with homegrown starters coming closer. In a season that has been filled with more than its fair share of stumbles for the Sox, the emergence of the young pitcher has been a significant step in the right direction.