Catcher David Ross is one of those players.
"You can't measure David Ross' value by number of at-bats or what the batting average is," said Red Sox manager John Farrell. "We know he can be a productive player. But his vision, his view of the game, he's a leader in the role that he's in, but in games that he's not in the lineup he's almost like having another coach on the bench, as observant as he is, things that he picks up inside of the game.
"And I know pitchers have gained instant respect and a lot of confidence in his game-calling abilities. He's so engaged with getting the most out of a pitcher on a given day that they have tremendous trust in him. He gives them a lot of confidence just by not only his game calling but how he talks to them in between innings. So David Ross can't be measured in numbers by any means."
Ross joined the Red Sox before last season, signing a two-year, $6.2 million contract. It was his second stint in Boston after a brief eight-game stretch in 2008. So, the Red Sox had some familiarity with him. But Ross, who is entering his 13th big league season, also brought a solid resume and reputation with him.
"He's got such a strong reputation," Farrell said. "And we did have the benefit of a month in  that he was with us. So there was some initial familiarity. But I think until you see over 162 games, I will say when he had the concussions he was missed, and when he came back he injected that intangible back into the group and guys fed off of that."
Daniel Butler has been in big league camp the last two springs, watching and learning from the veteran Ross.
"He's tremendously easy to talk to and very informative," said Butler, who played catcher in 72 games for Triple-A Pawtucket last season. "You can tell he knows pretty much any answer to any question you ask him. He's so smart in the aspects of the game. But it makes it even better because he's so easy to talk to and so open-minded.
"I look at how he communicates with the staff, and he's very positive toward everything he does, always has that positive outlook for whatever the pitcher does. He doesn't really bring up the negative -- not that he doesn't bring it up later -- but he always seems to bring up the positives out there."
Ross was brought in last season to back up Jarrod Saltalamacchia but with the intent that he would play more than a typical backup catcher. Two concussions, though, put him on the disabled list for 65 games, and he was limited to just 36 games. After returning from his second DL stint, he hit .270, including .280 in nine games in September, well above his .216 season average.
His performance earned him the starting-catcher's job in the final three games of the World Series. Ross had been to the postseason four other times in his career -- in 2004 with the Dodgers, in '08 with the Red Sox and in '10 and '12 with the Braves. Last season was his first World Series championship.
Ross, who will turn 37 on March 19, reported to camp fully healthy, is healed from both concussions and does not have any physical limitations. He will be partnered with A.J. Pierzynski this season, again as the backup, but again as more than a typical backup. Farrell has said he would like Pierzynski, who turned 37 in December, to catch about 100-110 games, with Ross catching 50-60.
"It's always actually fun for me," Ross said of working with a new partner. "It's nice to get to know guys. I feel like I have a ton to learn. I learned a ton from Salty and I feel like I'll have a ton to learn from A.J. I'm looking forward to getting to know him, see how he goes about his business, maybe I can pick up something that helps me out, whether it's catching or hitting. I like to pick those guys' brains.
"I know this is said a lot, but you never stop learning in baseball. And that's the best thing about when you get to continue to compete at this high of a level and compete with the best. That guy's got a great resume and I'm just looking forward to getting to know him and his secrets that can maybe help me out a little bit."