Sancho, 18, left the Etihad Stadium for better first-team opportunities in Germany and enjoyed swift progress before earning his first England call-up last year. He and Sterling have been reunited in the Three Lions camp for the international break, and the latter told Sport360's Alam Khan of his first impression of Sancho at City:
"First day I'd seen him training with us, I was really happy to see such a talent.
"I always knew he'd become the player he has, for sure. From minute one. I was playing right back against him one day in pre-season training and he spun me back and I nearly did my back in. He's a great talent.
"When he first mentioned to me he was thinking about going abroad, even though he was a City player, I was happy to hear that from him. To see that confidence, it reminded me of myself when I went to Liverpool."
The Bundesliga sensation has made three appearances for the Three Lions and will hope to add to his England tally in the upcoming UEFA Euro 2020 qualifiers against Czech Republic and Montenegro.
Sterling, 24, joined the Citizens from Liverpool for £49 million in 2015 and has cemented his spot as one of Pep Guardiola's most prized assets.
Sancho, meanwhile, won't regret his move to the Westfalenstadion considering the success he's found over the past season-and-a-half. He has nine goals and 14 assists in 35 games this season.
He provided a game-winning assist for Marco Reus in Saturday's dramatic 3-2 win over Hertha Berlin, via Goal:
It's no surprise Sterling draws some parallels between their two careers, though Sancho was one of the first among a new batch of English youngsters searching for success abroad. Arsenal duo Reiss Nelson, 19, and Emile Smith Rowe, 18, are on loan at Bundesliga clubs Hoffenheim and RB Leipzig, respectively.
Sancho joined Dortmund for £8 million a little less than two years ago but has more recently been reported as having a £100 million price tag, per James Ducker of the Telegraph.
The Black and Yellows were clearly aware of the talent they purchased considering he had yet to make a senior appearance at the time, though it's likely even they've been surprised just how effective he's been.
Squawka highlighted his provisional contributions in the league this term as on par with five-time Ballon d'Or winner Lionel Messi:
It didn't take long for Sterling to notice Sancho's promise, either, with England manager Gareth Southgate hoping his pair of wide stars can combine to great effect on the international stage.