Playing his first match since losing the Australian Open final to Marat Safin on January 30, Hewitt will open the grasscourt tie against a player who finished 2004 ranked 131st in the world.
Australian number two Wayne Arthurs, winner of his first career title in Arizona last weekend, will then play Austrian number one Jurgen Melzer in the second singles match.
A victory for Hewitt over the right-handed Peya would put added pressure on Melzer to stop Australia opening a commanding 2-0 lead before Saturday's doubles.
"Hopefully I can go out there and get the boys off to a good start and put a lot of pressure on Melzer," said Hewitt, who has declared himself fully fit after struggling with a hip injury during the Australian Open.
"Hopefully we're in for a big day tomorrow," he said.
The 24-year-old Peya is playing in his ninth Davis Cup tie but has a modest 1-1 singles record.
He said he would not be overawed against the aggressive 2002 Wimbledon champion in a tie to be played on a temporary grass court at Sydney's International Tennis Centre.
"Of course I have to play well, I'm playing the number two player in the world," Peya said on Thursday.
"I'm going to fight out there and that's all I can do. I like to play on grass. I guess he likes it too," he said.
THREE POINTS
Melzer said he did not expect to face extra pressure against Arthurs if Hewitt beats Peya as expected.
"I think every match is important. In the end you need three points, no matter how you get them," Melzer said.
Davis Cup champions for a 28th time in 2003, Australia are looking to atone for a poor result last year when they were beaten in the first round by Sweden and then overcame Morocco in a play-off to stay in the world group.
Captain John Fitzgerald avoided the temptation to use Hewitt in Saturday's doubles, deciding instead to stick with the big-serving left-hander Arthurs and Todd Woodbridge, Australia's most successful Davis Cup doubles player.
They will play Peya and Julian Knowle, who beat Britons Tim Henman and Greg Rusedski in the doubles rubber of a play-off tie victory last September.
Fitzgerald, however, said his thinking could change after Friday's singles.
"It might depend a bit on what happens on the first day. A tie sort of evolves and gets a life of its own," he said.
