Tom Wood has praised "stalwart" Calum Clark following the flanker's positive displays for the Northampton Saints so far this season.
The 25-year-old has played his part in the Saints' run of five wins from seven games this campaign, particularly catching the eye in the 20-11 European Rugby Champions Cup defeat at the hands of Racing Metro last weekend.
"Cal's got a huge engine," the Northampton Chronicle quotes Wood as saying. "He's full of heart and desire and he puts his body on the line week in, week out.
"He hasn't had a huge amount of luck with injuries and suspensions and he's been in the trenches a lot when the internationals have been away from Saints. He's an absolute stalwart, he grafts, he leads during the week doing his own thing. He's very professional.
"He gets his reward in big games playing like he does. He's a warrior in there for us and we rely a lot on him for energy and physicality. He's very good at the breakdown, a big heavy man, and much heavier than you'd think for his agility and his work rate. He goes really well in our pack."
Northampton are currently top of the Aviva Premiership table.