Waghorn recently returned from a lengthy spell out with injury and could start for the Gers against Hibernian in the final of the Scottish Cup at Hampden Park in Glasgow later this month.
The 26-year-old forward was in blistering form before he suffered a knee injury in February, having found the net 28 times in all competitions for the Ibrox outfit.
Miller believes that the former Sunderland and Leicester City forward would have added more goals to his tally had he been fit throughout the season.
“You see the number of goals Martyn [Waghorn] got in the six or seven months that he played – and there is no doubt he would have kicked on and got close to 40 had he been fit, so it’s all credit to the team, the way we play, and the chances we create,” Miller told Rangers’ official website.
Waghorn would have certainly scored more goals had he been fit and played regularly over the past few weeks.
Thankfully for Rangers, the Gers did not miss him much, as they wrapped up the Scottish Championship title with ease.
Mark Warburton’s side have also clinched the Scottish Challenge Cup and have progressed to the final of the Scottish Cup.