Humphreys underwent surgery on his back after acute pain meant his withdrawal from the Five Nations' Championship game against Ireland, but has fought to put himself back in the international frame.
There can be no better stage on which to impress your national coach - Graham Henry in this case - than a Swalec Cup semi-final tie against the 10-times winners, Llanelli, just before Henry names his squad to tour Argentina.
The two teams lock horns today at Brewery Field, Bridgend, while tomorrow at Pontypridd, Swansea, fellow rebels and city slickers, meet Cross Keys of the First Division.
So what price an all-rebel final? Humphreys believes Cardiff can prevent Llanelli from reaching a 14th final. "Firstly, I am glad to be back after what seems to have been an eternity. Secondly I can think of no better way to prove myself than playing in a Cup final," he said.
Surprisingly Llanelli have omitted the Welsh lock Chris Wyatt, but Scott Quinnell, who played a significant part in Wales' victory over England at Wembley last Sunday, is named at No 8.
However, Colin Charvis, the Swansea and Wales flanker, will miss his side's game against Cross Keys after suffering a fractured cheekbone in the tackle from Tim Rodber that, indirectly, led to the winning try from Scott Gibbs.
Gibbs definitely plays, as does Garin Jenkins, but Arwel Thomas and Darren Morris are both struggling to be fit.
Keys' coach, David Rees, said, "The boys have been playing well this season and we will certainly give it our best shot."
Cardiff (v Llanelli, today, 5.30, Bridgend): M Rayer; S Hill, L Davies, G Thomas, C Morgan; L Jarvis, R Howley; S John, J Humphreys, D Young (capt), J Tait, D Jones, G Kacala, E Lewis, D Baugh.
Llanelli: B Hayward; W Proctor, N Boobyer, N Davies, S Finau; S Jones, R Moon; P Booth, R McBryde (capt), J Davies, V Cooper, M Voyle, H Jenkins, S Quinnell, I Boobyer.
Cross Keys (v Swansea, tomorrow, 2.30, Pontypridd): I Bebb; J Vernall, S Reed (capt), C Bushell, R Nichols; D Rees, C Ellis; I Evans, L Gardner, D Crimmins, N Kelly, M Price, J Powell, P Watkins, S Gardner.
Swansea: D Weatherley; R Rees, M Taylor, S Gibbs (capt), M Robinson; A Thomas or L Davies, R Jones; D Morris or C Loader, G Jenkins, B Evans, T Maullin, A Moore, P Moriarty, L Jones, D Thomas.