The 22-year-old winger was controversially left out of Joachim Loew’s World Cup squad, with Germany going on to spectacularly crash out of the tournament at the group stage.
Guardiola was just as surprised as anyone that the talented young German was not taken to Russia, however, he has challenged the player to overcome adversity and said he will become better in doing so.
“Life is not easy. There are ups and downs, sometimes bad moments, it is how you react in those moments that will make you stronger,” Guardiola said.
“If he is able to overcome that situation, he will be a better player.
“If he doesn’t, he will not complete. So that is the target for Leroy.”
Sane was voted PFA young player of the year by his fellow professionals in a season where he scored 14 goals and totalled 19 assists in all competitions.
“He made an amazing season last time but it is just one,” Guardiola said.
“And you have do another and another one because the top, top players in history, every season they are always there.”
Guardiola knows what it takes to represent your country at a World Cup, having been part of the Spanish side that reached the quarter-finals in 1994, and has backed Sane to play at the highest level in the future.
“His target is to be consistent. If that happens, he will be back in the national team,” Guardiola said.
“Sooner or later he is going to play a European Cup and a World Cup.
“In two seasons, we have a European Cup again so the challenge is there.
“It was of course a sad situation for him and I can understand that. But it is over and he must look to the next one.”