Northampton director of rugby Jim Mallinder has praised the form of Teimana Harrison after he was named man-of-the-match against Racing 92.
The openside flanker impressed in the 9-9 draw at Franklin's Gardens on Friday as the Saints kept in touch with their rivals in the pool.
And after the game, Mallinder applauded the 23-year-old, who has been playing well in the absence of the injured Tom Wood and Calum Clark.
"He has always had natural ability but that is not good enough at this level," the boss told BBC Radio Northampton.
"You have got to be a smart rugby player as well and I think that is what he has improved."
He added: "You also need physicality and Harrison played like a wild man in the first couple of years and got himself injured but he has worked hard on his physique and his tactics."