Shields are currently seven points clear at the top of the division, although their lead was cut slightly last week after consecutive 1-1 draws.
Nearest challengers Hyde United also have a difficult challenge on their hands as they prepare to visit Matlock Town.
The Gladiators are just three points adrift of the play-offs, while Hyde will be out to consolidate second place in the league after back-to-back wins.
The pick of the other action sees in-form Guiseley host third-placed Radcliffe.
Guiseley have picked up 20 points from their last 10 matches in the league, and such a run has seen them move to within touching distance of the top five.
Meanwhile, Warrington Town and Marine, the two sides which could finish the weekend outside of the top five if results go against them, will visit relegation-threatened Marske United and Liversedge respectively.
All fixtures will take place on Saturday 25 February at 3pm, unless stated otherwise.
Fixtures - Saturday 25 February
Ashton United v Gainsborough Trinity
Bamber Bridge v Atherton Collieries
Belper Town v South Shields
Guiseley v Radcliffe
Lancaster City v Whitby Town
Liversedge v Marine
Marske United v Warrington Town
Matlock Town v Hyde United
Morpeth Town v Nantwich Town
Stalybridge Celtic v Stafford Rangers
Warrington Rylands v FC United of Manchester
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