"That whole drive home, I'm driving and all I could think about was, 'What's gonna happen?'" Joseph recalled almost two weeks later. "I'm like 'What's going on?' I don't think I said more than four or five words on the car ride."
A few hours later, Joseph got confirmation that he had been traded to the Phillies. Once back at Double-A Richmond's ballpark, he packed up his bags, said his goodbyes and switched clubhouses to join Philadelphia's Double-A Reading affiliate, which coincidentally played Richmond that night.
Two weeks removed from his 21st birthday, Joseph became the centerpiece of the July 31 non-waiver Trade Deadline deal that sent Hunter Pence to the Giants. He instantly became the Phils' top-ranked position prospect. MLB.com's Prospect Watch ranks Joseph the fourth best in the organization, behind pitchers Trevor May, Jesse Biddle and Brody Colvin.
So what's it like being the guy traded for Pence?
"It's cool," Joseph said before a recent game at FirstEnergy Stadium. "I'd never been on ESPN or MLB Network before this season -- when I got to play in the Futures Game and now getting traded -- so family and friends are having fun with it back home [in Phoenix], seeing it on TV and stuff."
The consensus among scouting reports is that Joseph's bat is a little ahead of his defense. However, Reading manager Dusty Wathan -- a former catcher, and the son of former Major League catcher and manager John Wathan -- has been impressed with Joseph's skills, especially considering his age.
"Watching him from afar, I was impressed with him," said Wathan, who described Joseph as a quiet leader. "And now being up close and personal with him, I think [he's been] even more impressive. ... He walked in Day 1 and I think guys respected him right away. That's a special thing when you've got a catcher that age who can go out and handle things the way he does."
In the 2009 First-Year Player Draft, long after Stephen Strasburg and Mike Trout were off the board, the Giants made Joseph, of Horizon High School in Arizona, the 55th overall pick. He played 117 games at low Class A Augusta before playing the entire 2011 season at high Class A San Jose, where he hit 22 home runs and drove in 95 runs.
In 2012, before the trade, Joseph was batting .260 with eight home runs and 38 RBIs with Richmond. In 17 games since switching clubhouses, he's struggled from the batter's box, batting .217 with a home run and three RBIs. He's struck out 23 times in 60 plate appearances, and admits he needs to work on his plate discipline.
But overall, the Phillies are happy with Joseph's adjustment to their organization. They're also pleased he will get the chance to refine his catching skills under Wathan.
"Our scouts like him," said Phils assistant general manager Benny Looper, who watched Joseph and Reading for three games early last week. "Our staff likes him here. I've liked what I've seen so far."
Joseph's new pitchers like throwing to him, too. May, the Phillies' top-ranked prospect, lauded the way Joseph takes control of the pregame pitcher-catcher meetings and converses in the dugout between innings.
"He's figuring us out really good," May said. "Young guy, but he's beyond his years. It's ridiculous. He just turned 21."
"I love his arm," Wathan said. "Great mind, strong hands. There are some things we can clean up with his receiving and his throwing. That will be cleaned up over the next couple months and over the winter."
While with the Giants, Joseph played in the SiriusXM All-Star Futures Game on July 8 in Kansas City. He drew a key walk and hit a go-ahead RBI double in what he called the greatest experience of his baseball career thus far. He was awed by the opportunity to play for Hall of Famer George Brett, who managed the U.S. team.
The Futures Game experience made Joseph hungrier to get to the big leagues, a path that, until July 31, was blocked by Giants All-Star catcher Buster Posey, who is only 25. Joseph, who said he learned from Posey during Spring Training, has nothing but praise for the Giants' starting catcher.
"He was just somebody that I always wanted to learn from, because it seems that every day, he's doing something right and doing something to help the team," Joseph said. "That's ultimately what I want to be."
With Joseph in the fold, the Phillies organization is in good shape at catcher. Behind All-Star Carlos Ruiz in the Majors, Triple-A Lehigh Valley's Sebastian Valle and Joseph both come highly regarded.
Wathan, for one, sees big things in Joseph's future.
"I think the sky's the limit for him," Wathan said. "I can see him being an everyday catcher in the big leagues."
Jake Kaplan is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.