Pep Guardiola has been impressed by Jadon Sancho at Borussia Dortmund but is unsure if the winger would have had a similar impact at Manchester City.
Sancho opted against signing a new deal with the reigning Premier League champions and instead headed to the Bundesliga in August 2017 for a reported £8million fee.
After making 12 league appearances in his debut season, the teenager has become a key component of Lucien Favre's side in 2018-19, helping Dortmund establish themselves as title contenders in Germany.
His club form led to international recognition with England at the end of last year, rewarding his decision not to take the "challenge" of competing for first-team minutes at City, according to Guardiola.
"I don't know. He didn't want to take this challenge, this opportunity to discover if he was able to," Guardiola told the media.
"He decided to go there. So, it's perfect. It's going well and congratulations on what he is doing.
"He is doing an incredible performance. He did it incredibly well this season. What would have happened this season [at City]? I don't know.
"Again, with the players, it depends on them and what they do on the pitch."
While Sancho decided to move on, fellow youngster Phil Foden remains at the Etihad Stadium and has enjoyed a greater role this season.
Foden scored his first Champions League goal in the 7-0 thrashing of Schalke in midweek but Guardiola is keen to temper expectations surrounding the 18-year-old, particularly with suggestions he could be elevated into the England fold in the near future.
"That's maybe a good decision," Guardiola replied when asked about Foden not playing for England at Euro 2020. "Don't make them play a lot of minutes. If they play a lot of minutes, everyone is going to be demanding they play for the national team.
"Of course, he can play more minutes, but he could play less. We cannot forget he is 18 years old and it's the first season he's played incredible minutes in the first team.
"He's played in the EFL Cup semi-finals, in competitions where normally you can't take a risk. He played Premier League when there were still a lot of games. He played important games. He played the Community Shield. So, he's played a lot of minutes and he'll play more in the future.
"The process has to be calm. How many young players go immediately to the international team and after that disappear from the map? We want him to stay 10 seasons or 11 or 12 with us, playing regularly, and every season he will be stronger and stronger.
"He's an incredible talent but he still has a lot of things to improve. It's simple for his age. At his age he needs time to grow and to be created. He's 18 years old. It's important he knows he is able to play with us and he knows we can trust him. That is the most important thing."
|Wales fresh for Slovakia clash – Giggs|
|ES Tunis to face CS Constantine in CAF Champions League quarter-finals|
|Renato Sanches ´not happy´ at Bayern Munich|
|Germany 1 Serbia 1: Goretzka salvages draw for Low´s new-look side|
|Wales 1 Trinidad and Tobago 0: Woodburn late show boosts Giggs|
|Germany fans pay tribute to axed trio Hummels, Muller and Boateng|
|Bucks forward Mirotic out two to four weeks|
|Mourinho sacked due to results, not player power – Pogba|
|Lukaku out of Russia game, Belgium boss Martinez confirms|
|Tudor replaces Nicola at Udinese|
|Bert van Marwijk appointed by UAE|
|Klostermann handed Germany debut, Neuer preferred to Ter Stegen in new-look team|
|Halep brings in Dobre as new coach|
|NRL Opta facts: Burgess and Murray out to repeat strong starts in round two|
|Harper happy Trout blew him out the water|
|Morata unsurprised by reported Man City interest in Saul|
|Injured Alexander-Arnold pulls out of England squad|
|Martinez wants Icardi resolution|
|Morata defends Simeone from criticism|
|Pogba: Real Madrid is a dream for anyone|
|Tierney joins Robertson in missing Kazakhstan-Scotland|
|Ichiro´s standing ovation & A´s pitching woes - Five things you may have missed from MLB opener|
|De Jong asked Koeman for Barcelona advice|
|Proteas duo Ngidi and Nortje ruled out of IPL|
|Meet Brody Oliver - The engineering graduate set to test his NFL mettle|
|Rayo Vallecano reappoint Paco Jemez|
|Neres, Rice, Zaniolo and the most exciting debutants of the international break|
|Giroud hints at Lyon interest|
|PRB confirms all four Welsh regions will remain next season|
|Salah goals will come again, believes Klopp|
|Casillas to end career at Porto after signing new deal|
|Pogba wants Solskjaer to get permanent Manchester United job|
|Vunipola defends captain Farrell|
|Crazy season is testing Tottenham´s character, says Rose|
|Anscombe warns of potential Wales exodus|
|54 shots and lose 1-0 - Nacional Potosi suffer ultimate smash-and-grab defeat|
|Middleton: Bucks itching for the playoffs|
|SANZAAR to clarify Super Rugby future amid reports of Sunwolves axe|
|Trippier admits he ´could have done better´ for Tottenham|
|Thompson non-committal over World Cup|
|Heaton hails ´outstanding´ England rival Pickford|
|Ronaldo doesn´t have to prove anything – Cancelo|
|Bucks hand Lakers fourth consecutive loss|
|Menotti worried about ´very tired´ Messi|
|Gabriel Jesus: Post-World Cup most difficult moment of career|
|Rockets´ James Harden makes NBA history|
|Musso honoured to have Messi back with Argentina|
|Clippers coach Rivers denies report he´s interested in Lakers job|
|Former Packers linebacker Matthews signs with Rams|
|MLB preview: Projecting AL East|
|Raiders sign linebacker Burfict|
|Adrien´s a prisoner at PSG – Rabiot´s mother slams Ligue 1 champs|
|Navas criticises Solari over lack of Madrid chances|
|Vinicius: I chose Madrid project over Barca money|
|Griezmann´s sister denies Barcelona contact|
|Barkley on Beckham trade: I was sad to see him go|
|Fleming steps down as Stars head coach|
|Rain washes out Miami Open as Andreescu prepares for action|
|PSG condemn ex-Manchester United defender Evra´s comments|
|Cowboys sign former Packers wide receiver Cobb|
|Nations League glory would top World Cup run, says Kane|
|Chelsea star Hazard ´not working´ on Real Madrid move|
|Retiring Safarova set for Prague swansong|
|Giggs fires back at Ibrahimovic´s ´Circle of Ferguson´ jibe|
|Sterling ´spot on´ with media criticism, says England team-mate Rose|
|Miller times it right as South Africa take super route to victory|
|Panthers sign DE Bruce Irvin|
|Blues sign Wales wing Adams|
|Man Utd fan McGregor reveals admiration for Ronaldo, Ferguson and Solskjaer|
|PSG confirm knee injuries for Meunier and Alves|