"We're very lucky to have a changing room full of winners, a lot of leaders in there.
You've got James Forrest, Callum McGregor, Ali (Johnston), Cameron Carter-Vickers, so many that understand what it is to be a Celtic player."
Sinisalo stressed that past achievements matter less than the immediate performance demanded in the upcoming fixture.
"In football, especially at a huge club like this, the most important game is your next one," he said.
He also tracked the success of former Aston Villa teammate John McGinn, who won the Europa League with Aston Villa.
"I did watch it," Sinisalo said. "I thought they were excellent.
Genuinely, I'm so happy for John."
Sinisalo remains focused solely on the imminent 90 to 120 minutes of football against Neil Lennon's side.
"There's 90 minutes, 120 minutes of football ahead of us, so you can't really think of what's ahead after the game," he said.
He recalled McGinn's advice about playing for Celtic in Glasgow.
"Initially when I signed, I remember speaking to him about it, and he gave me some lowdown on what to expect as a Celtic player being in Glasgow."
Sinisalo discussed his desire to permanently cement his position as the long-term number one at Parkhead.
"I've always said it, I want to play for this football club as a number one," he said.
He expressed gratitude for the opportunity given by O'Neill during the Europa League match against VfB Stuttgart on February 26.
"And to have that chance I've got to be really grateful to the manager for putting me in at Stuttgart."
