FORT MYERS, Fla. – It is spring training, and the Red Sox clubhouse is crammed. There are 61 players whom the team will have in major league camp, and nearly half of those will be unfamiliar to the public, individuals who have virtually no shot at breaking camp with the Sox and who, consequently, are perceived as all but irrelevant.

But that is not how the Red Sox staff sees things.

There are established members of the Red Sox for whom spring training is muscle memory. Players like David Ortiz will get his at-bats in; Jon Lester will get his requisite innings load to prepare for the season.

They need little guidance in Fort Myers. The Sox will care very little about their performance. They will be trusted to get themselves ready for the season.

In many respects, it is the players on the margins whom the Sox care most about during the spring. It is those players – the ones who may be competing for the 24th or 25th spot on the Opening Day roster, or those who seem like little more than organizational depth – who can determine whether a team successfully navigates the 162-game course of a baseball season.

The fate of the season may end up in the hands of left-handers Randy Williams or Andrew Miller, or prospects Kyle Weiland or Alex Wilson. Perhaps the team will need Che-Hsuan Lin or Larry Sutton to withstand a run of injuries, hoping that they can become the next Darnell McDonald or Nick Green.

The Sox are mindful of that notion. And so, it is those players who will receive a great deal of attention during the spring.

“I think we want to get the most out of everyone who comes in that door. That’s exciting,” Sox manager Terry Francona said on Sunday. “A lot of these guys aren’t going to make our club. It’s not even realistic.

“But that doesn’t mean we don’t want them to have a successful camp where we can get a grasp on what we think they are, either for later in the season or for their development. We probably end up spending more time on the younger kids – certainly the guys we don’t know.”

Injuries are inevitable. Players who once seemed irrelevant are suddenly thrust into crucial situations. One need look no further than last year – when players such as McDonald, Daniel Nava, Scott Atchison and Felix Doubront became key contributors – to realize the impact that such individuals can have.

Atchison went from an unknown to a member of the Opening Day roster, endured a few shuttles between Pawtucket and the majors and then finally stuck as one of the team’s most trusted relievers. Nava and Doubront started the 2010 season in the minors, but the Sox were able to get a feel for the impact they could make while in spring training last year.

As for McDonald, he spent most of spring training in 2010 trying to recover from an oblique injury. Unprompted, in Francona’s daily media sessions during spring training, the manager would offer regular injury updates on McDonald.

At the time, it was the sort of thing that was barely worthy of a line in a blog entry or notebook. In retrospect, the fact that Francona and the Sox staff did take such an interest in a non-roster invitee proved meaningful.

McDonald – who was called up in April, slammed a walkoff hit in his Sox debut and ended up playing 117 games in the majors, second most among team outfielders – certainly viewed it that way.

“It means a lot. From Day 1, they made me feel a part of the organization,” McDonald said last year. “It was a disappointment to me that I was injured. That’s tough. Coming to a new organization, you want to showcase what you can do in front of the big league staff. It just says a lot about the people they have here, the scouting, and Tito for sure that they hung in with me. It paid off.

“I’ve been called up to the big leagues before where it’s like you’re just there. You don’t really feel part of the team,” McDonald continued. “They do such a good job of, Day 1, come in, sit down with Tito, [GM Theo Epstein]. They tell you kind of what the expectations are, what your role is going to be.

“They eliminate that gray area where it’s like, ‘Do I have a chance? Do I not?’ I knew from Day 1 that it was going to be a depth thing, and if someone got hurt, I’d get an opportunity. That’s all I ask for.”

The Sox are convinced of the potential importance of such players, and so they take steps to ensure that they feel integrated into the clubhouse in hopes of putting those players in a position where they feel comfortable enough to perform.

The front office and coaching staff spent the past weekend in meetings – one day to discuss the pitchers, another to focus on position players – in order to define spring training plans for everyone in camp. But they also began taking steps to ensure that every one of the non-roster invitees, every shy prospect in big league camp, will feel like a part of the team’s major league club.

“We have video, we have headshots and we have extensive reports [of every player],” Sox manager Terry Francona explained last season. “The reason why we have the headshots is so that when they walk in the door, every staff member can call them by the first name. We think that’s important. Darnell McDonald can walk in the first day and it’s like, ‘Hey, D – welcome.’

“We actually spend more time on those guys than we do on David Ortiz, because we don’t actually know them. We want everyone to feel that, when they walk in our door, they’re part of what we’re doing. It’s just something we believe in. I think it helps.”

It is a small thing, but it can be meaningful. Players who enter the season as afterthoughts can mean the difference between a team that overcomes injuries and one that falls victim to them.

That is something that Francona seems particularly well positioned to appreciate. After all, he spent much of his career on the bubble, fighting in spring training to earn one of the final spots on the roster. He understands what it means in such a role to be welcomed and what it is to be ignored by a staff.

Whether informed by that experience or not, he has established a culture in the Red Sox clubhouse. The manager has worked to create an atmosphere in which any player wearing a Boston uniform is made to feel as if he is more than just passing through.

“I don’t feel like you should treat people on their talent,” said Francona. “Treat people right and try to get them to play as good as they can.”

It is an approach based not just on decency and dignity, but also on the best interests of the club.