Like Sancho, Matondo spent three years in City's youth academy before being signed by Schalke in early 2019 and given a more direct route to first-team football.
Still just 19, the Welsh winger has already made eight Bundesliga appearances and scored his first goal against Leipzig in September.
"If I can do as well as he has done so far then I will be really happy. He is a great player," Matondo said of Sancho.
"I have always known that since being at Manchester City with him, how good he can be and how good he will be. Hopefully he can help me as well.
"Obviously at Manchester City it is tough, all the players are top players. It wasn't that I couldn't see a pathway - I believe in myself.
"But it was more that I had the opportunity to go and play first-team football and at the time I didn't have that at Manchester City. I preferred to play first-team football so I took the opportunity.
"When I was younger I always believed in myself. I always thought: you will be playing at a good level when you are 17, 18, 19.
"That's what I am doing at the moment and hopefully I can keep improving."
Now a part of the Wales national team and deemed a talent by manager Ryan Giggs, Matondo is looking to keep his head down in Germany and continue impressing.
The teenager has even become hooked on Gordon Ramsey videos in an attempt to become a better cook and give his body the best possible diet.
"I go on Gordon Ramsay a lot on YouTube and see what you can cook up - I try to copy," he said.
"It's not quite similar but I try my best. I am not around any distractions of living in Cardiff or Manchester with my friends.
"It's nice to be around your friends but [living] alone I just do more for myself. That's improved me. I am doing little extras, going to the gym and eating good food."