Here are a couple examples:
Phillies closer Brad Lidge remembers a game when Ruiz, who teammates call "Chooch," had a nice day at the plate. He might have hit a home run. He might have had one or two more hits or two or three more RBIs. He cannot remember the specifics, but he can remember how Ruiz chucked his glove into his locker after the game. He can remember how he sat there with his head in his hands.
The Phillies had won, but his pitchers had struggled.
It made Ruiz visibly upset.
"This guy absolutely cares more about the team than he does about himself," Lidge said. "He's never happy if he does well at the plate. He's only happy if the pitchers do well."
Phillies left-hander J.C. Romero nodded in agreement as he heard the story.
"I remember him going up to Little Roy [Oswalt] or Big Roy [Halladay] after we won a game this year," Romero said. "He went up to him and said, 'I'll do better next time. I was bad today.' That was something that really stuck with me. He takes a lot of pride in calling the games. That's what makes him so good. It doesn't matter how he's doing at the plate. He wants to call the right game to give the team a chance to win."
Ruiz is having a career year. He hit .302 with eight home runs and 53 RBIs in 121 games. Of the 18 catchers in baseball with 400 or more plate appearances this season, Ruiz ranked second in on-base percentage (.400), third in batting and OPS (.847), fourth in doubles (28) and ninth in slugging (.447). But just as important, he ranked fourth in catcher's ERA (3.31).
He hopes his success continues Wednesday, when the Phillies play the Cincinnati Reds in Game 1 of the National League Division Series at Citizens Bank Park.
His first priority is making Roy Halladay's postseason debut a good one.
"That's my job," Ruiz said. "Help my pitchers. When they do real good, I'm happy. No matter what game I have offensively. If I don't get a hit I still feel very good. That's the first thing. Sometimes they come up to me and say, 'Hey, I know you didn't get a hit today, but you did good.' I'm like, 'Yeah, I'm happy. I'm happy because of you.'"
An informal poll conducted this weekend in Atlanta revealed Ruiz is perhaps the most well-liked player in the clubhouse.
Ryan Madson got numerous mentions.
They also mentioned Raul Ibanez, Mike Sweeney and Kyle Kendrick.
But if Ruiz wasn't the first player mentioned, he was second or third.
"He's genuine," Phillies bullpen coach Mick Billmeyer said.
He also is funny.
Players kill countless hours in the clubhouse during rain delays, and it is then Ruiz might break out impressions of teammates, often following Billmeyer, who also is known for his impressions. Ruiz memorably impersonated former Phillies center fielder Aaron Rowand, putting on wrist bands, shin guard and squatting with a bat in his hand, perfectly mimicking Rowand's unique batting stance.
Ruiz also impersonates some of his pitchers' quirks on the mound.
Oswalt is a cleaner in the bullpen. He does not throw many pitches, but he constantly is smoothing the dirt in front of him with his feet. Danys Baez is always adjusting himself, grabbing his jersey, adjusting his cup. Kendrick looks in for the sign, agrees to the pitch, then pauses after he agrees to the pitch.
"He's real good at them," Billmeyer said.
"I try to have fun," Ruiz said. "The guys like [the impressions]. It's a game. You try to relax and have fun. But you know when it's a good time to do it because when it's game time, you've got to be ready. But it's good because it keeps everybody happy."
But Ruiz knows what makes him happy. Halladay getting into a groove, throwing seven, eight or nine brilliant innings and the Phillies taking a 1-0 lead in the best-of-five series. If Ruiz comes up with a big hit, great. (Ruiz is a .303 career hitter in the postseason.) If he does not, that's OK. As long as the team does well.
And that's why his teammates like him so much.
"He takes a lot of pride in getting the most out of every guy that steps on the mound that day," pitching coach Rich Dubee said. "Catching a shutout or catching a guy through a tough time or getting an big out, that absolutely means more to him than getting three hits."
Todd Zolecki is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.