Boro boss Kelly confirmed Dawson will sit the game out due to an ongoing pelvic plate issue that has been hampering him recently.
Defender Isaac Assenso is Boro's only other absentee as Josh Barrett, who limped off early in their 3-1 win over Radcliffe last weekend, is fit enough to be named on the bench.
Kelly's men sit in eighth spot in the BetVictor Northern Premier League, with 47 points from 33 games, but their chances of making the play-offs appear to be slim as all of the sides above them have games in hand.
Their hosts this weekend Ashton are battling relegation, currently languishing in 18th spot, just one point outside the drop zone.
Michael Clegg's men will be gunning for revenge after they suffered a 3-1 defeat at the Flamingo Land Stadium last month.
United are unbeaten since their defeat at the hands of Kelly's men, beating Witton Albion 3-1 before 1-1 draws against Whitby Town and promotion contenders Warrington Town.