Ibrox side Rangers will take on Hibernian in the final of the Scottish Cup later this month.
Waghorn recently made his comeback from a long-term injury and is now fully fit. The 26-year-old forward is likely to start for Rangers against Hibernian in the final of the Scottish Cup at Hampden Park in Glasgow later this month.
The former Sunderland and Leicester City man is one of the best players at Rangers at the moment and has been the best striker in the Scottish Championship this season.
McKay, who is just 21 years of age and has enjoyed a very productive season, has shared the discussion he recently had with Waghorn regarding his comeback plans.
“Waggy's been a massive player for us this season,” the Scotland Under-21 international told The Daily Mail. “I've been speaking to him recently and he told me that he just needed a couple of games under his belt before the final.
“He's done that and he made an impact against St Mirren. Waggy's a great pro and he's looked after himself, which is why it didn't look as though he'd been out for 11 weeks.
“I know just how hard he's worked at his rehab in order to get back for the final. He probably could have played before he did but the last thing we wanted was to rush him back. But it's such a big boost to see him back.”
Rangers have won the Scottish Championship title this season and have gained automatic promotion to the Scottish Premiership for the 2016-17 campaign.
The Gers have also clinched the Scottish Challenge Cup, and winning the Scottish Cup this month will see them claim the treble.