Definition of put someone on their mettle in English:

put someone on their mettle

phrase

  • (of a demanding situation) test someone's ability to face difficulties.

    ‘there were regular public meetings where local MPs were put on their mettle and remorselessly pilloried’
    • ‘This way of thinking was made explicit only when critics such as Vincenzo Borghini were put on their mettle to defend the Baptistery's antiquity.’
    • ‘Coventry's opening was brisk and sufficiently to the point to put Tottenham on their mettle.’