Mark McCall believes that Maro Itoje will only get better with time, having seen the promising youngster commit his long-term future to Saracens.
The 20-year-old has previously captained England to Junior World Cup success, while he has also already made 20 appearances for Sarries.
Speaking to the North London club's official website, McCall said: "Maro's progress over the last two seasons has been outstanding. He has an incredible desire and hunger to get better as a player.
"What is even more impressive is he has managed to combine his progression as a rugby player alongside his studies, in which he is also excelling. He's an incredibly ambitious young man, and we are delighted to announce he will be extending his stay with Saracens."
Itoje, who skippered Saracens' victorious LV= Cup side this season, added: "Saracens are a great club who have treated me unbelievably well since I joined at the age of 14. The club feels like home, and I'm really excited to have extended my contract."
Saracens are currently second in the Aviva Premiership table.
