In the text message, he said he was "scared inside the stadium," his cousin John Stow said, adding: "He doesn't use that term loosely."
A short time later, after the game had ended, the 42-year-old paramedic and father of two walked out to look for a taxi and was attacked so brutally that he remains in a coma with a brain injury.
On Tuesday, Bryan Stow's family gathered outside Los Angeles County-USC Medical Center and thanked well-wishers in Los Angeles, San Francisco and around the country for their support.
As the Dodgers head to San Francisco next week for the Giants' opening home stand, Stow's family called for civility among rival sports fans and asked those who saw anything or know the assailants to help detectives arrest those responsible.
"We would like to use this as a rallying cry to stop unnecessary violence in our greatest pastime and all other sports, not only here but abroad," said John Stow, wearing a Giants cap and jersey.
"So I ask for one last thing on behalf of Bryan -- that we all enjoy a safe and competitive and exciting year of baseball."
He described the beating as "a terrible tragedy done by cowardly people," but said he was reassured by people who are outraged and appalled.
At Tuesday's news conference, County-USC doctors explained the severity of Stow's condition. They said he suffered a severely fractured skull and damage to the frontal lobe of his brain.
The left side of his skull has been removed to allow his swollen brain to decompress. And even without sedation, he probably would still be in a coma, said Dr. Gabriel Zada, his neurologist.
"It's going to be a long recovery process," Zada said.
Bryan Stow's sister Erin Collins also thanked the people of Los Angeles for their support for her brother, a Santa Cruz paramedic who made the road trip to Southern California for opening day.
"We know they weren't true Dodger fans," Collins said of the assailants.
Los Angeles Police Department detectives said they believe as many as 100 people may have witnessed the attack, which occurred about 8:30 p.m. Thursday in Parking Lot 2 at Dodger Stadium.
Det. Jose Carrillo said he believes the two assailants may have assaulted three or four other men before beating Stow.
The Los Angeles City Council has voted to offer a $50,000 reward for information leading to the arrest and conviction of the attackers, bringing the total reward to $100,000.
Los Angeles County Supervisor Michael D. Antonovich offered a $10,000 reward, the San Francisco Giants offered $10,000 and American Medical Response, the company where Stow works as a paramedic in Santa Clara County, offered $5,000. The Dodgers matched those previous rewards with a pledge of $25,000 on Monday.
"Violence like this will not be tolerated and I encourage anyone with knowledge of the attack to assist the LAPD in their investigation," Los Angeles Mayor Antonio Villaraigosa said.
The mayor has described the attack as "completely without any provocation." The victim was "hit from behind" and "beat senselessly," Villaraigosa said.
Tipsters can call LA Crime Stoppers at (800) 222-8477, text the letters TIPLA plus the tip to CRIMES (274637), or use the website lacrimestoppers.org.
Times staff writer Kate Linthicum contributed to this report.