But their excitement has been tempered somewhat after he posted a video saying that the move to LA was "like the beginning of my retirement."
Hernandez, known to many as Chicharito, was speaking to his parents on his YouTube show "Naked Humans."
And in the emotional phone call, Hernandez broke down in tears as he talks about the move.
"We're saying goodbye to a career we put a lot of effort into, and we worked, and I know you guys feel it," the 31-year-old Mexican striker said.
"And we're gonna look at the bright side and it's going to be amazing, but whether we like it or not, we are retiring from the European dream."
There's a tradition among aging footballers from European teams who are approaching the twilight of their careers to make one final move to the MLS before retiring.
European greats Andrea Pirlo, Thierry Henry, Frank Lampard and Steven Gerrard all ended their playing careers in the United States.
Even Zlatan Ibrahimovi -- whom Hernandez is replacing at LA Galaxy -- was 37 when he signed in 2018.
But in his introductory press conference, Hernandez -- who is Mexico's all-time top goal scorer with 52 goals in 109 games -- clarified his comments.
"It's so simple. I think all over the world, but [especially] in my country we love and we are like obsessed with drama and excess," he said.
"And so when you say 'retirement' it's like 'Oh, tomorrow he's going to announce retirement.'
"They didn't really listen to what I said: 'the beginning of the retirement.' The retirement could last 10 years, you never know."
The club reportedly paid $10 million for Hernandez's services and will make him the highest paid player in the league on an annual salary reported to be in the region of $6 million.
Hernandez left his native Mexico in 2010 to join Manchester United and he's made 344 career appearances for United, Real Madrid, Bayer Leverkusen, West Ham United and Sevilla, scoring 127 goals.
But the payoff of signing Hernandez could be far greater than any fee or wages LA Galaxy spend on the Mexican superstar, since he's untouchable for Mexico in goal-scoring and arguably the nation's greatest ever player, adored and idolized like few before him.
"Chicharito is an outstanding player," Mexican Football Federation president Yon de Luisa told CNN.
"He's the Mexican national team's leading scorer historically and I am sure he is going to have an outstanding participation here in LA."