As noted by Jeff Sentell of DawgNation.com, the break was in his non-throwing hand. Per that report: "The event took place during a boating incident. The exact details of the event could not be specifically confirmed other than a tow rope got away while dragging another rider and Fromm put his hand up to shield himself from the rope."
Sentell added that Fromm will "only need a few weeks to heal" and "should be ready to go for the start of fall camp."
Head coach Kirby Smart confirmed the injury, per ESPN.com's Chris Low.
It's Fromm's second offseason injury. Last month, he got a fishing lure lodged in his leg.
"Well, I was fishing, and it was getting dark," he said of that accident, per Jay Clemons of 11Alive.com. "My buddy and I were fishing at the top of the water. ... He tried to set the lure, and the lure came flying back at me, and it gets stuck in my leg. The rest is pretty much history."
Fromm, 19, took over as Georgia's starting quarterback last season after Jacob Eason suffered an injury in Week 1. He promptly led the Bulldogs to the College Football Playoff National Championship, throwing for 2,615 yards, 24 touchdowns and seven interceptions while completing 62.2 percent of his passes. He also rushed for 79 yards and another three scores.
Georgia, led by a stout defense and a devastating run game, didn't need Fromm to play hero ball, and he managed the offense ably in the team's 13-2 season. While they fell short against Alabama in the title game, it was still a superb season for the Bulldogs.
The Bulldogs aren't exactly wanting for options at the position, however, as 5-star recruit Justin Fields—the No. 2 overall prospect in the class of 2018, per 247Sports.com—is waiting in the wings.
The dual-threat Fields was expected to play some role for the Bulldogs in the 2018 season, and perhaps even win the job over Fromm, though the incumbent isn't worried that the quarterback competition will affect the locker room.
"It's part of the team aspect that's out there," Fromm said, per David Paschall of the Times Free Press. "Obviously you're buddies with guys in your room, because you see them every day and you're with them every day. We're also competing for a job and competing the best way we can. The main goal is to help the team the best way we possibly can."