A fatigued Swans outfit fell short of an AFL grand final berth after Fremantle pulled off a fourth-quarter comeback to claim a 12-point preliminary final win at the SCG.
The hosts had soared to a game-high 28-point lead in the third quarter despite missing injured captain Callum Mills and the five players banned in the fallout from the Pullman Hotel scandal.
Those filling the void were youngsters Jesse Dattoli (nine games), Harry Kyle (13), Billy Cootee (12) and Tom Hanily (16).
Hanily had helped build Sydney's early ascendancy, capitalising on star forward Tom Papley's work by scoring a sensational dribbling goal in the first quarter.
Teenaged defender Kyle stood up against Fremantle's star-studded forward line with six contested possessions and seven intercept possessions.
Senior leader Rowbottom, who finished with 14 touches and seven tackles, was bolstered by the grit shown by their young talent.
Asked if he had thought Sydney would come within touching distance of the grand final last month, the midfielder said: "It's funny you say that, I definitely would have.
"This time last year, probably not.
"But I think the exposure these young guys have had over the first half of this year and the belief that they've got themselves and the trust that we have in them is something that didn't really faze us.
"They're stepping in, and as we've seen over the last couple of weeks, it shows why we do believe them."
Sydney coach Dean Cox's message throughout their finals campaign boiled down to the old football cliche of sticking to roles, adamant there was no need for superheroes to replace their missing personnel.
And the Swans remained true to that adage against Fremantle before being overcome by fatigue.
Key defender Tom McCartin and stand-in captain Dane Rampe were impressive in helping Sydney maintain a 19-point lead at half-time despite trailing the forward entry count 27 to Fremantle's 31.
So diligent was the backline structure that Dockers star Patrick Voss only registered his first disposal at the end of the second quarter, while Josh Treacy and Jye Amiss had a combined seven touches.
"The pride that we've got in this group and what we've been able to deliver, regardless of who's out there," Rowbottom said.
"We take ultimate belief in our game plan and our system, and no matter who's out there, we believe that we can win.
"The last couple of weeks have shown that, and we'll take that into next year."
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