The game will be an important test for the 36-year-old as he hopes to get some valuable game-time in preparation for an anticipated return to the Ulster side for their October 26 Magners League derby encounter with Leinster at Ravenhill.
With the World Cup final taking centre stage this weekend and no Magners League fixtures on the bill, Ulster find themselves without a game. The "A" match will provide some of the province's senior players with the opportunity to try and put the three recent league defeats to Edinburgh, the Newport Gwent Dragons and the Llanelli Scarlets behind them.
Tomorrow night in Dublin, Humphreys will form an experienced half-back partnership with Kieran Campbell in a back-line that also includes Simon Danielli, Seamus Mallon and Paul McKenzie, as well as development players Mark Kettyle and Darren Cave.
The Ulster "A" coaching team of Clem Boyd, Neil Doak and Gary Longwell have selected a youthful pack of forwards, fronted up by Declan Fitzpatrick and Tim Barker, who at 24 and 26 years of age respectively are the old men of the pack.
Along with Academy member Thomas Anderson, who has spent the summer training with the senior squad, Chris Henry and David Pollock form what looks an all-action back row.
'A' Interprovincial fixture list
ULSTER "A": Mark Kettyle (Belfast Harlequins); Simon Danielli (Malone), Darren Cave (Belfast Harlequins), Seamus Mallon (Ballymena), Paul McKenzie (Belfast Harlequins); David Humphreys (Dungannon), Kieran Campbell (Dungannon); Niall Conlon (Belfast Harlequins), Stuart Philpott (Belfast Harlequins), Declan Fitzpatrick (Belfast Harlequins), Filo Paulo (Malone), Tim Barker (Dungannon), Thomas Anderson (Dungannon), Chris Henry (Ballymena), David Pollock (Dungannon).
Replacements: Simon Shawe (Ballymena), Matt Miles (Ballynahinch), Willie Faloon (Ballynahinch), Mark Robinson (Queen's University), Sam McDonald (Malone), Paul Marshall (Belfast Harlequins), Kieran Hallett (Malone), Ian Whitten (Queen's University).