The phrase "some of the younger guys" applies to almost everyone on the A's pitching staff this spring. And even seven-year veteran Chris Resop, who came over from Pittsburgh during the offseason, has given Jaso his vote of confidence already.
"I don't shake," Resop said. "What he puts down I throw, because obviously he knows these hitters better than I do."
The 29-year-old Jaso has spent four seasons catching in the American League -- the first three with Tampa Bay and the last with division-rival Seattle.
He certainly feels comfortable dissecting the at-bats of opposing hitters, but there's still plenty to work on this spring. For now, his focus will remain on learning the other half of the battery the best he can.
"What makes them tick?" Jaso said. "Each of their personalities. If they start getting away from the strike zone, when I go out there to the mound, how do I talk to them? How do I get them to re-focus?"
Jaso came to the A's in the same trade that sent Michael Morse from the Nationals to the Mariners. This spring, he's competing for the starting job with Derek Norris, but it's likely both will see plenty of time during the season. The left-handed-hitting Jaso may have the edge, simply because the A's will face righties more frequently.
But that's manager Bob Melvin's decision, and he won't be making it strictly for offensive purposes. That's why he's making sure Jaso gets comfortable with as many pitchers as possible this spring.
"He's gotten along here very well with these guys," Melvin said. "There is a learning curve to it, and we've got quite a few guys with some stuff. It's one thing to catch them in a bullpen, but it's another to catch them in a game, when the intensity is more so and the movement is more so."
Jaso, who played in 108 games last season and hit .276 with 10 homers and 50 RBIs, admitted he probably won't be fully accustomed to the new staff by the start of the season. It's a process that doesn't happen overnight.
Jaso pointed to Brandon League's sinker as an example of the adjustments he had to make in Seattle last year. Early on, Jaso had a tough time picking up where League's ball would finish, but by midseason, he had sorted that out and his instincts were able to answer the question for him.
"He knows the hitters, and as soon as he learns us pitchers, he'll know exactly what pitches we need to throw to get those hitters out," said right-hander Dan Straily, who has thrown to Jaso in both of his spring starts. "He already knows what those guys are trying to do, and he can take that knowledge and help us."
Righty Jarrod Parker praised Jaso's willingness to learn the styles of an entire staff.
"He's a smart dude," Parker said. "He's here early. He's working with us, and he comes out early and he's around us. I think that's all you can do -- try to learn as much about us and the style we all have."
Last season, Jaso went 3-for-4 against Parker with a homer, a triple and a walk.
This time around, Parker is happy to have Jaso on his team, and he feels Jaso has the personality to fit right in.
"We don't have a real tough staff to catch," Parker said. "We have an easygoing group, and the way we're easygoing works with him, because I think he's kind of the same way."
Jaso certainly hopes so. He was on the outside looking in last season as the A's cruised through September to an improbable AL West title.
"Last year when I was playing against these guys, it looked like they were having a lot of fun over on their side of the field," Jaso said. "They're definitely keeping baseball the way it's supposed to be played. It's been an easy atmosphere to come in here and be a part of."