A Selwyn win would see the team go at least four points clear of FC Twenty 11 with a round remaining, which would be enough to stay in the Southern League.
Unbeaten Christchurch United and second-placed Cashmere Technical have already sewn up the top two spots, while FC are likely to take home the wooden spoon this season.
Last month, Coastal looked to be competing with Technical for second spot, but a 3-2 loss to Nelson Suburbs all but halted their chances.
Retaining the Hurley Shield will now be Coastal’s aim after Technical confirmed a place in the National League with a series of wins in the last month.
Coastal secured the silverware with a shock 3-2 win over Technical in July, but have not played a Christchurch-based team at home since.
The last time Coastal and Selwyn met in a Southern League clash it was a tight battle, with Coastal taking the win 3-2 in May.
Following their Chatham Cup semi-final win, Christchurch United take on Green Island and FC Twenty 11 on Sunday and Tuesday respectively.
Wins in both games would see United secure the Southern League title for another year.
Technical will look to add to their 38 points with a win over Ferrymead Bays at home.
They go into the match following a comfortable 3-1 win over Nomads in a catch-up game last week.
Meanwhile, Nomads host Nelson Suburbs on Saturday at Tulett Park.
