An exceptional performance and MVP honors in the Arizona Fall League followed, so surely Desme was close to getting a call, most assumed -- if not for a trip to The Show, then at least for an invitation to Spring Training.
Yet, Desme insists he'd already received the call long before his final at-bat in the fall came and went -- the one that would take him to bigger and better places.
It just so happens it wasn't what the A's organization -- or anyone else, for that matter -- had in mind.
The call, Desme announced Friday, came in the form of priesthood in the Catholic church.
"Last year before the season started, I really had a strong feeling of a calling and a real strong desire to follow it," the 23-year-old said. "I just fought it."
Thus, Desme chose to play out the season as a test of sorts, "just hoping and praying about it."
"As the year went on," he said, "God blessed me. I had a better year than I could have imagined, but that reconfirmed my desire because I wasn't at peace with where I was at. I love the game, but I aspire to higher things.
"I thought, I'm doing well in baseball, but I really had to get down to the bottom of things -- what was good in my life, what I wanted to do with my life. And I felt that while baseball is a good thing and I love playing, I thought it was selfish of me to be doing that when I really felt that God was calling me more, which took me awhile in my life to really trust and open up to it and aim full steam toward Him."
The telling result: A phone call on Thursday to relay his life-changing choice to A's general manager Billy Beane, who chose Desme as the club's second-round pick in the 2007 First-Year Player Draft.
Beane's reaction to the news was "great," says Desme, who claimed to be even more taken aback than the team's head honcho during the conversation.
"I was surprised [Thursday] when I called Billy to inform him about my decision," Desme says. "I was interested to see how I was going to react, knowing that when that phone call was over I'd be done with baseball most likely for the rest of my life. I was able to experience a great amount of peace because of it.
"I want to give my life completely to God out of love because of everything He's done for me. Something like this is even very little compared to what He's done for me."
-- Grant Desme
"It just reconfirmed me of my decision, and it also made me realize that I had already detached myself from baseball awhile ago."
However, the numbers didn't show said feelings, and the A's were more than ready to start their No. 8 prospect -- recently deemed by Baseball America -- at Double-A Midland this season. After all, Desme's breakout year not only produced a .288 batting average and 89 RBIs, but also a clean bill of health for his ailing hamstring, wrist and shoulder.
"From a talent perspective," said Oakland's director of player personnel, Billy Owens, "it's pretty self-explanatory as for his numbers as to the type of player he is."
Adds A's scouting director Eric Kubota, who admitted to being in "disbelief" upon hearing the news: "I think people, in general, were just happy for Grant because he had an injury-free year for the first time. It really looked like, baseball-wise, he was on the fast track and going in the right direction."
He was, in fact, heading right where he needed to be -- despite not being where the baseball community wanted him to be.
"My injuries, I would say, would be the biggest blessing God's ever given me," he said. "For my entire life, baseball's been my life. I define myself as a baseball player, and when it was taken away from me, it was an eye-opener. It was a real shock that it could end. I realized that even if I played in the big leagues, it was still going to end, or it could end anytime you step on the field with an injury. I really started doing some soul searching of who I was and who I wanted to be, and this is where that's led me."
It's a place those close to Desme have come to embrace and appreciate, much to the outfielder's utmost appreciation.
"If that's what he wants to get into, then more power to him," said Daniel Haigwood, who played with Desme at Class A Stockton. "I have strong beliefs myself, so I think that shows how devoted he is to his religion. I'm sure he thought about it long and hard, and I really respect him for it."
Said a scout who's watched Desme since high school: "It was a little bit shocking since he was knocking on the big league door, but his faith has always been important to him, so in some ways it's not that shocking. I have a lot of respect for the young man."
Desme, a lifelong Catholic who grew up with a strong religious family in Bakersfield before attending Cal Poly-San Luis Obispo, has just as much respect for the game he's walking away from -- the same game he credits with aiding in his decision.
"Whenever I was able to talk to someone about God, or help someone, that made coming to the ballpark more enjoyable," he said. "I looked forward to that.
"During my last game in the fall league, I hit a home run and proceeded to strike out twice, which was kind of ironic since that defined my career a bit. I knew there was a good chance it would be my last game, but there was no sad feeling. I figured whatever God wants is going to happen, and I'm going to pursue that."
So now, the brave Desme faces what he says is a 10-year path to becoming a priest while studying at St. Michael's Abbey in Orange County beginning in August.
"It's like I'm re-entering the Minor Leagues," he said.
And while Desme has yet to fully process his life without baseball, he's certain his future will not include regrets.
"I want to give my life completely to God out of love because of everything He's done for me," he said. "Something like this is even very little compared to what He's done for me."