Perez's contract with Formula One's dominant champions runs out at the end of the season and the 34-year-old faces an uncertain future.
Former Force India, Aston Martin and Alpine principal Szafnauer told reporters 'Checo' would be his choice and he had said as much at a recent F1 event in Abu Dhabi.
"I said 'knowing Checo as well as I do, I would replace Checo with Checo'. If I were (team boss) Christian (Horner), I would still keep him there for next year," he said.
"He's had some lows. This year, from what I can see, apart from a couple of races where I think he should have finished a bit higher, he's doing it."
Perez is second in the standings after five races, with three seconds and a third and this weekend returns to Miami where last year he took pole position and finished runner-up to Verstappen.
The Mexican spent seven seasons at the Force India/Racing Point team, now Aston Martin, before racing for Red Bull from 2021.
Verstappen, whose own future remains subject to some speculation with Mercedes making overtures, won 19 of 22 races last year and has started 2024 with four wins from five, and Szafnauer said "Max is just better".
The American, who is currently on 'gardening leave' and promoting an Eventr travel app, said Perez had never been a great qualifier but racecraft was his strength.
"There are not many times that I can count where he worked for me where you think, 'Why did you do that in a race?'," he said.
"There's only one time I can remember, in Singapore, where he got frustrated and hit a Williams, but the rest of the time he is very, very good at overtaking without making mistakes... he's really, really good at it.
"When he was up against (Nico) Hulkenberg, Hulkenberg would always get him over a lap," he added. "But by the end of it, because Checo could manage his tyres, Checo would get him."
Hulkenberg, 36, has several more seasons ahead of him after being announced as a Sauber driver for 2025 and then Audi in 2026.
Seven-time world champion Lewis Hamilton will be 40 when he joins Ferrari from Mercedes next season while Aston Martin's double champion Fernando Alonso is 42.
