Pep Guardiola has told Raheem Sterling he must remain focused after the Manchester City forward's impressive start to the season.
Sterling was in sparkling form in City's emphatic 5-0 victory over Steaua Bucharest in their Champions League playoff first leg -- setting up the opening two goals and winning an early penalty that Sergio Aguero missed.
Guardiola has been full of praise for the England international but insists he can improve even further.
"Until now, Raheem is playing really good but he's only 21-years-old so he has to learn a lot," Guardiola said.
"The best advice is to keep calm and focus on his training, his body and his personal life. Then when that happens he has a lot of quality -- he's fast and has good work ethic.
"He can go byline or inside. When he comes inside to play he has the quality to link up with his teammates. He's a fantastic players and that's why I think [director of football] Txiki [Begiristain] and the club were so clever last summer to buy him."
Guardiola was delighted with his side's performance as they all-but secured their place in the Champions League group stage with an emphatic win in Romania.
Sergio Aguero scored a hat trick and David Silva and Nolito each scored once in a dominant performance in the first leg.
"We are almost in the Champions League, which was our target from the beginning," Guardiola said. "It was a great performance and great attitude from the players. We played really, really good, the result is amazing but it's the way we played which means I'm so satisfied. It's a big compliment for these fantastic players.
"All of the managers in the world want to create chances and to concede few, that's what we all want. OK, we are there, so now rest and then focus on Stoke and the second game."
Aguero could have had five goals but he missed two penalties in the first half. However, Guardiola wasn't overly concerned by the misses, particularly after he scored from the spot in Saturday's 2-1 win over Sunderland.
"Penalties are penalties," he said. "He has the personality to hit it and it's important he was not down, he was focused on the game and after he scored three goals."
Pep Guardiola was delighted to maintain his winning start as Manchester City manager as his side all-but secured their place in the Champions League group stage with a 5-0 win over Steaua Bucharest.
Sergio Aguero missed two penalties in the first 20 minutes but rediscovered his scoring touch to bag a hat trick with David Silva and Nolito also on target in the Romanian capital.
Guardiola again left goalkeeper Joe Hart on the bench, but saw his side dominate from start to finish as they eased to victory to leave Steaua with a seemingly impossible task in Manchester next week.
"We are almost in the Champions League and that was our target at the very beginning," Guardiola told BT Sport.
"It was a great performance, we played really, really good. The result is amazing but the way we played, I'm so satisfied and it's a big compliment to these fantastic players.
"All the managers in the world want to create chances and concede few. We are there so now it's rest and focus on our coming games."
Aguero's teammate Kevin De Bruyne was not overly concerned by the Argentina international's misses either.
"We play a good game and it's a really good advantage for next week," said the Belgian.
"In the end he scored three goals, so what can you do? If you score three goals nobody will complain about the penalties."