This season, the pair was split, with Brantly starting the season at Double-A Erie and Castellanos sent to Class A Advanced Lakeland.
Brantly said he was excited when Castellanos was promoted to the SeaWolves on June 5, but that excitement was tempered when Brantly was promoted to Toledo the very next day.
"I was kind of numb to [being promoted]," Brantly admitted. "Once it set in, then it was pretty exciting.
"The drive from Erie to Toledo was the shortest three-hour drive in my life. It felt like it happened in a flash, and I was in Toledo."
The promotion didn't just happen, of course. Brantly earned it by hitting .311 with three homers and 24 RBIs in 46 games with Erie. It helped that Brantly, who turned 23 on Saturday, was the toughest player in the Eastern League to strike out, fanning once every 11.5 plate appearances.
Defensively, he threw out 33 percent of potential base-stealers.
"I felt I came in with a good approach offensively and got off to a good start there," Brantly said of his time in Erie. "I was seeing the ball well. Defensively, I was trying to 'mature' my catching, because that is the reason [the Tigers] make a move like this."
Brantly said much of his work does not involve physical aspects of catching.
"I'm working on my communication with my pitchers," he said. "You can tell, in the pace of a game, when a catcher is on the same page with his pitcher and when he's not. You can see them working together.
"What's the body language like? Are you helping the pitcher or are you frustrating him?"
Since his promotion, Brantly has been helping out with the bat and with the glove. In his first 29 International League games, he batted .260 with five RBIs and 11 runs scored while throwing out 27.3 percent of the runners who tried to steal against him.
His solid play behind the plate, along with the return of catcher Bryan Holaday to Toledo, has given Mud Hens manager Phil Nevin a pleasant dilemma: Finding playing time for two prospects.
"Both of them are going to get their chances behind the plate," Nevin said. "We'll figure it out each day.
"Most of the time when Brantly's not catching, he's going to DH because we need to keep his bat going. But they both will get their time catching."
Brantly's fine play this season helped him reach one other dream -- getting a chance to play again with Castellanos. Both were teammates on the U.S. squad at the SiriusXM All-Star Futures Game in Kansas City.
"It's great to finally be playing with him," Brantly said after Castellanos was named MVP of that contest. "I got excited when I got to play with him one day in Double-A and then I got moved up.
"When we're in the lineup together, I don't know what it is, man. It's just something kind of electrifies him and we get it going."
Dry July: Syracuse has struggled this month, winning just once while losing 10 times, including the last seven and all three since the All-Star break. The Chiefs are hitting .206 while scoring 29 runs in 11 games (2.6 per contest), with eight runs coming in one contest. Of the 15 players who've come to bat for Syracuse this month, eight are hitting .217 or lower.
What a relief: Columbus LHP Eric Berger began the season as a starter, going 1-3 with a 5.28 ERA in six ganes. He moved to the bullpen early last month and has enjoyed plenty of success in his new role. In 10 relief appearances, Berger's 1-0 with a 1.40 ERA. Opponents hit .269 against him as a starter but just .179 when he comes out of the 'pen.
He said it: "Weird stuff has happened [when I try to make a Major League roster]. I've never really been able to go into a season [in the Majors] and say, 'OK, here I go.' And now the window of opportunity might be closing. But I'm looking for another opportunity, and most people don't even get one." -- Knights 1B Dan Johnson to the Charlotte Observer. Johnson, the 2010 IL MVP, has hit .274 and ranks second in the league with 22 homers and 64 RBIs.
He said it, part II: "I haven't lost the big picture yet. I'm trying to get better every day so that when an opportunity happens, I can go help out the big league team." -- Red Wings IF Tsuyoshi Nishioka to the Rochester Democrat & Chronicle. Nishioka is hitting .233 with one homer and 17 RBIs in 66 games with Rochester but delivered a key two-run double in the Wings' 4-3 victory over Toledo on July 12.