Fritz, the top-ranked American at world number 12, outlasted Tiafoe 4-6, 7-5, 4-6, 6-4, 6-1 in the semi-finals on Friday night to take a big step towards ending his country's 21-year wait for a men's Grand Slam champion.
Having become the first US man to reach a Grand Slam final since Andy Roddick at Wimbledon in 2009, Fritz said that he will relish his shot at glory.
"I've always enjoyed playing him (Sinner). To be honest, I don't think I'm going to be put in a more stressful situation than I was today," Fritz told reporters.
"I think today was much more stressful than me playing the final. I just feel good. I have a feeling I'm going to come out and play really well and win."
The match took place after Sinner defeated an ailing Jack Draper 7-5, 7-6(3), 6-2, with the hopes of a nation weighing heavy on the two Americans.
"Both of us want to be the guy to make it," said Fritz, who held a 6-1 advantage in head-to-head meetings with Tiafoe before the match.
"I'm not going into this thinking I'm the favourite because everything's totally different when you're playing a match like this," adding that Tiafoe had played unbelievable tennis during the US Open.
Fritz was beaten in three sets the last time he met Sinner, in the quarter-finals at Indian Wells last year, and he expects a huge test against a player who has since made his Grand Slam breakthrough by winning this year's Australian Open.
"He strikes, he hits the ball big, he's like a very strong ball striker, but I feel like I always hit the ball really nice off of his ball," Fritz said.
"I think I typically play well against him."
