Rangers beat Kilmarnock 2-1 in the Scottish Cup on Tuesday night.
The Gers picked up a dramatic victory in their Scottish Cup replay against Kilmarnock, as after a 0-0 draw first time around, Rangers came out on top this time with a 2-1 win.
It was Waghorn who opened the scoring, converting from the penalty spot after being fouled inside the penalty area with less than four minutes on the clock.
However, Kilmarnock hit back with a fine strike from Rory McKenzie, and the game appeared to be heading towards another draw, before Nicky Clark - who came on for Waghorn inside the first ten minutes - swooped to smash home from an injury-time corner kick.
The fans were delighted, but will now be worried about the situation surrounding Waghorn's injury, given that he took his tally for the season to 28 goals with that penalty against Kilmarnock.
In the process of winning the penalty, Waghorn picked up a knee injury, and manager Mark Warburton has told STV that the prolific striker left the stadium on crutches, but will know more about his injury later today.
"With Martyn it was one of those ones where he locked legs as he fell," said Warburton. "I don't know if he caught the surface or not but he has an abrasion on his knee. He took the penalty, credit to him, but we will see how he is. He is on crutches and we will see how he is in the morning," he added.