The Hornets are back in the top flight after a season in the Sky Bet Championship and begin their campaign at home to Aston Villa on Saturday.
Despite moving to Vicarage Road in 2017 Hernandez is yet to make his Watford debut, instead spending time out on loan at Huesca, Real Mallorca and Getafe.
The Colombia forward returned this summer, however, and is now ready to get his Watford career up and running - if manager Xisco Munoz gives him a shot against Villa after impressing during pre-season.
"I'm really looking forward to Saturday," Hernandez told the club's official website.
"I want to play and I'm available, but whatever the coach decides I will be here for him.
"I signed for Watford four years ago so I'm looking forward to playing here in this stadium in front of the fans, and the most important thing is that the season goes well for everyone.
"I'm very happy people had fun watching me in pre-season but pre-season doesn't count for anything.
"The important games are coming up so it's very important people can enjoy watching me from this Saturday in the Premier League."
For a player yet to kick a ball in the Premier League, Hernandez has huge ambitions as he aims for a career akin to that of Aguero.
The former Manchester City striker left England having become the Premier League's all-time leading foreign goalscorer - with Hernandez looking to emulate his fellow South American.
"He's a legend for Manchester City and my dream is to reach something similar to what he has achieved," added the 22-year-old.
"I know it is very tough but I will try my best to reach that level.
"I want to play, so it doesn't matter where on the pitch, if it's at striker or as a winger.
"Wherever they ask me to play I will play, as long as it is in one of the offensive positions it doesn't matter where, but I will always try to do my best."