Smith has suffered three defeats in his professional career but remains a high-level operator who is in the mix for a world title shot at 154lbs.
But those aspirations will disappear if he loses to Vargas – a boxer who has fought against some world-class opponents of his own.
Here’s all you need to know.
When is it?
Smith vs Vargas takes place at Madison Square Garden in New York City on Saturday 30 April on the undercard of Katie Taylor vs Amanda Serrano.
The ring walks are expected to take place at around 9pm local time (2am BST on Sunday 1 May).
How can I watch it?
Smith – 2/5
Vargas – 15/8
Draw – 25/1
Katie Taylor vs Amanda Serrano – (WBA, WBC, IBF, WBO women’s lightweight titles)
Jessie Vargas vs Liam Smith (super-welterweight)
Franchon Crews Dezurn vs Elin Cederroos (WBC, WBA, IBF and WBO super-middleweight titles)
Austin Williams vs Chordale Booker (middleweight)
Galal Yafai vs Miguel Cartagena (flyweight)
Reshat Mati vs Joe Eli Hernandez (super-lightweight)
Khalil Coe vs William Langston (light-heavyweight)