Mauricio Pochettino admits Erik Lamela is unrecognisable from the player he was two years ago after the winger's hat-trick helped Tottenham to a 4-1 win over Monaco.
The victory ensured Spurs go through to the Europa League last 32 as group winners and Lamela starred, bagging three in 37 minutes before Tom Carroll added a fourth late on. Monaco's Stephan El Shaarawy had scored a consolation for the visitors in the second half.
Lamela's treble continues his resurgence this season, with the Argentine finally starting to deliver on the ?26million Tottenham shelled out in August 2013.
"It is true that today he is more confident and looks a different player from two years ago," Pochettino said.
"There are always a lot of reasons for the improvement of a player. First of all, a young player like Lamela has arrived at a new country. He is a very special boy but he needed time to adapt and not only on the pitch.
"When you score a hat-trick you don't have to say anything more because it was great for him and great for the team. It helped the team to finish at the top.
"Lamela has not surprised me, he is a great talent and okay, you always need a little bit of luck to score but he scored three goals and its normal that he deserves all the praise and the headlines. That is football.
"Always the younger players need time. They need time to improve, they need time to adapt their game to a new culture and a new country and sometimes it is a difficult process. Some players are quick, some it takes time."
Tottenham's primary focus remains finishing in the top four but the Europa League offers another route in the Champions League, given the winners secure automatic qualification for Europe's top tournament.
Pochettino's side lost to Fiorentina in the last 32 last season and, despite being seeded, they could face another tough draw this year, as Valencia, Sevilla, Galatasaray, Shakhtar Donetsk and Borussia Dortmund all potentially lie in wait.
Spurs will, however, play their second leg at home and Pochettino believes that represents a worthwhile reward.
"It was important to win the group because we wanted the possibility to finish the tie at White Hart Lane, at home," Pochettino said.
"It will be first leg away and the second at home. It was the opposite way that we played last season against Fiorentina. That is important for us."
Monaco's defeat means they exit the tournament, having finished third in Group J behind Anderlecht.
"We just couldn't cope with Tottenham pressing us so high up the pitch. It led to individual errors and all those early goals," Monaco boss Leonardo Jardim said.
"I would have preferred to have had a much more experienced side as we struggle against really top sides like Tottenham."