The former Wigan Athletic striker has scored prolifically this season, netting 28 times in 34 appearances.
However, Waghorn was forced to miss Rangers’ match at the weekend against Queens of the South, after he picked up a knee injury.
Rangers managed to beat Queen of the South 1-0, but they lacked their usual attacking quality and McCann believes the Light Blues will struggle without their main striker.
“They miss Martyn Waghorn,” McCann said. “Not only for the amount of goals, but because of his work rate and the way he pulls people around. Mark plays with this three up top, and both him and Kenny Miller have a really good understanding.
“They have lost that little spark.”
Waghorn could be set to miss the rest of the season with his current injury problem, according to a report in the Scotsman.
In truth Rangers’ had not scored too many goals in many of their recent matches even when Waghorn was available.
Mark Warburton’s side had only netted five times in their last five matches which was down on their usual average over the campaign.
Rangers will need to prove that they can cope without Waghorn in the coming weeks as they look to protect their place at the top of the Scottish Championship table.
Warburton’s side are currently seven points clear of Hibernian at the top of the league, but Alan Stubbs’ side do have a game in hand.