West Ham United and Brentford have been watching him this summer, but Peck insists nothing has changed since he arrived at Bramall Lane as a wide-eyed 16-year-old.
"I joined when I was 16 and the gaffer's given me every debut since," Peck said after Sheffield United's 3-0 EFL Cup win at Mansfield Town this month. "From Premier League to Championship and in the cup.
"The staff as well, Mickey Collins. I've got a lot of stuff to pay back. They've helped me become the player I am today."
The 21-year-old was the final signing of Chris Wilder's first spell in charge, arriving from Arsenal in the summer of 2021. Jeorge Bird, who runs the Jeorge Bird Arsenal youth website, remembers a player the Gunners rated among their very best.
"Peck was very highly regarded when he was coming through the academy at Arsenal and was often seen as one of the club's best prospects," Bird told Football Presse.
"Yes it was quite a major surprise (when Peck left) but it was understandable from his perspective as he felt that he would get first-team opportunities quicker elsewhere.
"I think he would have made some first-team appearances for Arsenal but the level is so high that he would probably have had to move to another club eventually."
Bird believes it was Peck's polish, more than anything else, that marked him out even in an academy stocked with technicians.
"His technical ability always stood out at Arsenal," he said. "Even though Arsenal youth players are always renowned for their technique, he always seemed to be of a particularly high standard in that regard."
That judgement has been backed up in South Yorkshire. Peck spent a short loan at Oldham Athletic in the National League before working his way into Wilder's plans, making his senior debut as a substitute in a 1-0 Premier League win over Brentford in December 2023. He signed a new four-year contract the following August, scored his first senior goal in a 3-0 win over Portsmouth last November, and was named the club's David Spencer Young Player of the Year for the 2024-25 season.
Wilder has tracked the change up close.
"He's cool as a cucumber, that boy," the manager said back in September 2024, shortly after Peck had come off the bench to help see out a result. "Nothing fazes him so I'm not surprised. We prepared for Shacks to come on for Sydie but he was pressing late on, he made some really good decisions on the ball and we're delighted for him, he's a popular boy. He had some big shoes to fill and he certainly filled them."
Gary Weaver, working the Sky Sports Essential EFL podcast after Peck's introduction in a Steel City derby win, put it more bluntly still: "Sydie Peck, I love Sydie Peck. I think he's an excellent player, he obviously came on for Ollie Arblaster, the Blades fan who was injured in the first half, went off at half-time. And then United just saw it out in the end."
Peck has since become one of the first names on Wilder's teamsheet, and last season had to fend off fresh competition following the winter arrivals of Kalvin Phillips and Joe Rothwell. For the coming season, he is relishing the competition rather than fearing it.
"There are experienced midfield lads who have done it at the top level," Peck said. "Then there is me that is sort of right at the start of their career. I'm young. They do help me, I do learn. I like to think that I help them sometimes. But like I have said, we are together as a group and, nine times out of ten, I think if we get the midfield right, and we keep the ball out of one box and put the ball in the next in the other box, we will win games of football. It's as simple as that."
Boasting great passing ability - both long and short - Peck also displays excellent intelligence when in possession and with his running off the ball. The midfielder can be likened to a young Scott Parker, with a great ability - even at his youthful age - of being able to dictate the tempo of a game.
England have taken note too, with Peck progressing from the U17s through to a first England U21 cap last September, via a goalscoring U20 debut against Germany at Chesterfield.
Wilder has even joked about how missed Peck is whenever he's out of the side.
"I said to Sydie this week, it's amazing how good a player you are when you're not in the team," the manager said.
For now, Peck is refusing to be drawn on where his career goes next.
"At the end of the day, I'm still 21," he said. "Yet again, age is just a number, isn't it? I don't really look into that. All the talk and things like that. I've got a Sheffield United shirt on now. I'm a Sheffield United player. I'm signed to Sheffield United. That's my aim. My head's down."
Peck left Arsenal as a teenager convinced he'd find first-team football faster elsewhere. Four years on, with West Ham United and Brentford watching and England's youth sides still calling him up, that looks like a call he got right.