Rangers striker Waghorn is set to be out of action for up to eight weeks.
The forward was taken down in the Scottish Cup win over Kilmarnock on Tuesday, being fouled early in the game inside the penalty area.
He got up and carried on, scoring from the penalty spot to hand Rangers the lead, but he could not continue after that and was substituted off.
At the end of the game, with Rangers winning 2-1, Waghorn left Rugby Park on crutches, and it has since been confirmed that he will miss up to eight weeks of action as he recovers from a problem with his knee.
This is a big blow to Mark Warburton, who loses his top goalscorer for an extended period of time, as the Gers look to consolidate their place at the top of the Scottish Championship table.
With Waghorn’s injury confirmed, Kiernan - a fellow summer signing at Ibrox - took to his personal Twitter account to send a message of support to his teammate.