Given that the emergence of a new challenger for the national No 10 jersey would probably do more for Plaid Cymru's vote next Thursday than any number of party political broadcasts, the 20-year-old rookie carries a heavy burden into this afternoon's Swalec Cup final.
Having consigned Jonathan Davies to the replacements' bench, the goal- kicker will be very much on trial as Cardiff take on Swansea in a classic east-west confrontation amid the ruins of a half-demolished Arms Park. If his confidence levels are anything to go by, he has little to fear.
Alec Evans, the successful Australian coach who has just returned to Britain for a second stint at Cardiff, believes Jarvis possesses the strut and swagger to spark a dangerous-looking back division into meaningful action. With Rob Howley running hot at scrum-half - his three-try performance against Llanelli in the semi-final has already passed into rugby folklore - the "home" side go in with a definite edge.
Especially as Arwel Thomas, the current first-choice stand-off at Test level, will be conspicuous by his absence because of injury. Swansea will find it difficult to paper over that particular crack, although Mark Taylor, their centre, said yesterday: "What we have shown this season is a tremendous spirit that has helped us overcome appalling injury problems."
The way Jarvis has kicked this term, Swansea may end up wishing the Arms Park posts had been sold off early, along with an endless tonnage of other sentimental artefacts. His early penalties against Llanelli were instrumental to the outcome, as were his extraordinary long-range efforts against Bath in last autumn's epic Heineken Cup quarter-final.
Certainly, Davies has no axe to grind over the Cardiff selection. "Lee performed particularly well in the semi-final while I'm a little rusty, having not played much over the last month," he said. "I'm disappointed, obviously, but it's common sense that Lee should play today."
For Mike Ruddock, the Swansea coach, today's showpiece marks the end of a productive sojourn at St Helen's; he takes over as rugby director with Leinster next month. His departure will give the All Whites an emotional incentive to hit the heights this afternoon, but whether that will be enough to spike Jarvis's guns is another question entirely.
Cardiff: J Thomas; S Hill, L Davies, M Hall, N Walker; L Jarvis, R Howley; A Lewis, J Humphreys, L Mustoe, D Jones, K Stewart, H Taylor (capt), O Williams, G Jones. Replacements (probable): J Davies, J Hewlett, P Booth, P Young, J Wakeford, J Ringer.
Swansea: M Back; A Harris, M Taylor, S Gibbs, Simon Davies; A Williams, A Booth; I Buckett, G Jenkins (capt), S Evans, S Moore, P Arnold, A Reynolds, Stuart Davies, R Appleyard. Replacements: L Evans, R Jones, L Davies, D Niblo, K Colclough, E Evans.
Referee: D Davies (WRU).