Youngs is set to make his England debut against Fiji on Saturday after a total of just nine starts at hooker for Leicester in the Aviva Premiership and Heineken Cup.
It was only three years ago that Youngs began to make the transition from a hard-running centre on the recommendation of Heyneke Meyer, who was then Leicester's director of rugby and is now South Africa coach.
Much like Steve Thompson, who was originally a flanker, but he was identified early by Clive Woodward as England's 2003 World Cup hooker and mastered the role.
Rowntree concedes Youngs is being plunged into Test rugby sooner than he would have liked because of Dylan Hartley's knee injury but he believes the 25-year-old could develop into a top-class international.
"You can't expect Tom to be the finished article from day one but the signs are he is going to be a very, very good player going forward," Rowntree said.
"You have to learn at the coal face and he is learning quickly.
"I refer back to Dylan Hartley as a young hooker for England and Steve Thompson. They were learning for long periods, throwing under pressure."
Like Thompson before him, Youngs' most obvious weakness is the accuracy of his lineout throwing but Rowntree is excited by his all-round game.
"He has not had it all his own way in terms of the lineout," Rowntree said.
"What impresses me is how he has recovered from setbacks within games. He is a strong character and will get stronger and stronger.
"I have known Tom since he was in the Leicester academy and to make such a radical change (in position) is impressive. His performances are a stand-out.
"You have to be able to throw and scrummage under pressure. The things he brings outside that, the real dynamic stuff, sets him ahead of other people.
"Is he being pushed too quickly? I am not absolutely sure. The fact Dylan is injured means we have to look at him a bit earlier than we would have hoped to.
"But from what I am seeing the signs are he will pass the test at the top level. I have every confidence in him."
Youngs will be one of three uncapped players in England's 23-man squad to play Fiji, with Wasps lock Joe Launchbury and Saracens prop Mako Vunipola set for places on the bench.
Launchbury's selection came as something of a surprise, given he leapfrogged Mouritz Botha after just two days in the camp, but England have been impressed with his form for Wasps this season.
Botha and Harlequins lock George Robson were among 10 players released back to their clubs last night, a list that included loose-forwards James Haskell and Ben Morgan.
As a result, Thomas Waldrom appears to have retained the England number eight jersey while Tom Wood and Tom Johnson have both been preferred to Haskell and are vying to start at blindside flanker.
Wood has been included in an England match-day squad for the first time in nearly 14 injury-plagued months. The Northampton flanker's last appearance was against Romania at the World Cup.
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