The 24-year-old was handed the gloves for the Parkhead side after Kasper Schmeichel's long-term shoulder injury and has made his presence known.
He became first choice for his country after getting the nod over veteran keeper Lukas Hradecky, helping Finland to a 2-0 win over hosts New Zealand in the FIFA Series.
Sinisalo won praise for his performances at Ibrox, with Celtic winning a penalty shootout in the Scottish Cup quarter finals after two missed penalties from Rangers’ James Tavernier and Djeidi Gassama.
The goalkeeper did his best to throw the Rangers stars off ahead of the penalty kicks, drawing inspiration from Argentina hero Martinez, whom he has previously worked with.
Sinisalo, formerly an understudy to the 2022 World Cup Golden Glove winner at Aston Villa, said: "It would have been stupid of me not to have asked Emiliano for advice when I worked with him.
"So I tried to take certain things from what he does during that shootout at Ibrox."
Sinisalo admitted he doesn't go "as far" as Martinez in his antics, but he takes on board a few tips to create his own version of the experienced shot-stopper's routine.
Aside from the penalty shootout, he described the Old Firm match as "very cool" but tried to manage his excitement by treating it as a normal game.
The young goalkeeper reflected on an eventful season in Scottish football, labelling it as "It's been a season that probably couldn't have been scripted and won't happen again very often."
He feels sad for Schmeichel and hopes the veteran keeper's injury isn't "a career-ending thing."
Sinisalo always had aspirations to play and acknowledged the responsibility that comes with it, saying: "When the moment comes, you have to perform and keep the shirt. A goalkeeper is only as good as his last match."
The shot-stopper also showed his determination by flying halfway around the world to represent Finland, starting against New Zealand in preference to the experienced Finnish captain Hradecky.
He explained that the long-distance travel didn't affect him personally or Celtic, stating: "I feel very proud and honoured to play against New Zealand. I was told I would play the day before.
"I have to be honest, travelling the long distance hasn't felt any different personally. It's fine."
His dedication to both his club and country was evident as he explained the careful preparation required for the lengthy journey.
Both Celtic and the Football Association equipped him with advice to ensure he was in prime condition upon arrival.
Sinisalo shared: "The flight was long, but both Celtic and the Football Association told me how to approach the flight, to be in the best possible condition when I arrived.
"You had to do the things that needed to be done. Whether it was with sleep or making sure your body has enough water.
"Everything was fine and we have prepared well. There were no problems personally."