put somebody on their mettle
put (one) on (one's) mettle
To put one in a situation in which they must prove their worth, skill, or ability. Being promoted to general manager at such a young age is certainly going to put her on her mettle. Our goal is to put each of these athletes on their mettle to see who earns the spot on the team.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
put somebody on their ˈmettlemake somebody do the best work they can, or perform as well as they can: The school inspection is going to put the teachers on their mettle.
Farlex Partner Idioms Dictionary © Farlex 2017