Fa'asuamaleaui, 26, left camp on the Sunshine Coast late last week after his father's passing to spend time with his family.
He re-joined teammates in Melbourne on Sunday night and trained with the side on Tuesday before playing in his 17th State of Origin match for Queensland on Wednesday night.
Last year, Munster's father Steven died while the Maroons were in camp on the Sunshine Coast preparing for the decider in Sydney.
He left camp to grieve with his family before returning to play an inspirational and emotional role in a famous 24-12 win.
"We have obviously gone through some tough times me and Tino so I know exactly how he is feeling," Munster said on Tuesday.
"When you lose your mentor or an idol or a role model of your family, especially your dad, it does take a heavy toll on you.
"I know Fereti will be very proud of the man and father he has become. We all talk about rugby league accolades, but the values Fereti put in Tino ... I am sure he will be a very proud dad tomorrow night regardless of the result.
"We know what Tino is about and we are right behind him, as is every Queenslander, rugby league in general and NSW. Hopefully he can play the footy Fereti would be proud of."
Last week while his father was still alive, Fa'asuamaleaui spoke candidly of how he was cherishing every moment with his dad.
"He is always in my heart, no matter what," he said.
"I will always play for him."
He has spoken on several occasions of "the butterfly effect" that followed Fereti's decision to leave Samoa and play with the Sydney Roosters after being recruited by former Tricolours captain Arthur Beetson.
Fereti played lower grades with the Roosters before moving to Gympie in regional Queensland, where he had three children with wife Dianne - daughter Olivia and sons Iszac and Tino.
Tino rose through the junior system to become a star of the game, a premiership winner with Melbourne in 2020 and a Maroons and Australia regular.
"Where I am in my career now and playing for Queensland, it really all started when Arthur recruited my old man," he said.
Fa'asuamaleaui, also the Gold Coast co-captain, had been travelling to see his father for an extended period during his illness.
He would travel to Gympie after Titans training and on his days off.
The tough forward was suffering in silence while still putting in each week for his club.
Maroons forward Kurt Capewell said Fa'asuamaleaui was the kind of person who "does anything for his teammates" which is one reason why he has decided to play in the match.
"I can't imagine what it's like to go through," Capewell said.
"All we can do is get around him and be there for him."