A season of unpredictability has so far gone reasonably well for both clubs. Both have been in transition in recent seasons but their meetings remain up there with the big games in the domestic calendar - if only, at the moment, in deference of their being the leading honours winners.
Remarkably, they go into tonight's game at Oriel Park with identical recent form: just two points separate them in the table.
Arguably, it's a bigger game for Dundalk who know they can leapfrog Rovers and jump two places into fourth in the table if they win.
Manager Jim McLaughlin is without midfielder Paul Carlyle, who starts a three-match suspension, while both striker Peter Withnell, who retired from the Bohemians match last week with a recurrence of a calf injury, and full-back Shane Reddish, still unfit following a rib injury, are both very doubtful. Fintan McConville, who replaced Withnell last week, may expect to start.
Rovers have Mark O'Neill back from suspension but manager Mick Byrne may stick with an unchanged side despite its poor performance in Ballybofey last Saturday night.
Byrne will expect a return to the commitment his players showed in the wins over Sligo and Bohemians which was, by all accounts, lacking at Finn Park.
Last two seasons: 1996/97: Dundalk 4 Shamrock Rovers 1, Shamrock Rovers 0 Dundalk 2, Dundalk 1 Shamrock Rovers 3. 97/98: Shamrock Rovers 1 Dundalk 2.
Recent league form: Dundalk: LWWWL; Shamrock Rovers: LWWWL.
Leading scorers: Dundalk: Byrne and Melvin 5; Rovers: Cousins 10.
Betting: 2/1 Dundalk, 11/8 Rovers, 2/1 draw.
Referee: G Perry (Dublin).
Cork City will be without both Stephen Napier and Jason Kabia, two of their most influential players this season, for their FAI Cup first-round tie with Bohemians at Dalymount Park on January 9th. They received two-match suspensions yesterday for reaching 20 penalty points.
Bohemians' central defender, Maurice O'Driscoll, has received the minimum one-game suspension following his sending off against Shamrock Rovers last Friday week. He misses their league game with Drogheda on January 2nd but will be available for the cup match with Cork.
The Finn Harps pair of Jonathan Minnock and Davy Dowling have received two-match bans, also for accumulating five bookings, and will miss the league game with Cork and the cup clash with Bray Wanderers.
Suspensions: 2 matches; Dowling and Minnock (both Finn Harps), Kabia and Napier (both Cork City), Murphy (Monaghan United), Whyte (Limerick FC), Harkin (Waterford United); 1 match: O'Driscoll (Bohemians), O'Neill (Monaghan United).
Suspensions start on the week beginning December 29th.