Clark Keltie is to return to the club having been freed by Rochdale.
The 26-year-old has been training with Darlington for a month following short loan spells with Chester and Gateshead.
He is expected to put pen to paper on a six-month contract on Monday, but two Irish players have already signed deals with Quakers.
Tadhg Purcell and Gary Dempsey have both arrived having left their clubs in the League of Ireland.
Purcell, 24, can play either as a striker or on the wing and joins from Shamrock Rovers for whom he played against Real Madrid last summer.
The Spanish giants gave Cristiano Ronaldo his first appearance in a friendly match against the Irish side.
Dempsey, 28, is more experienced and counts Dunfermline, Aberdeen and Yeovil among his previous clubs.
He joins Quakers from St Patrick's Athletic for whom he played in the UEFA Cup last season.
All three must wait for their debuts as Darlington's game at Bury on Saturday has been postponed.