article: The experiment will begin when the first round takes place on Saturday 24 September. It is an initiative being introduced by the Scottish FA after recent talks with the International Football Association Board. Previously, teams could only use three of seven substitutes in Scotland's premier cup competition. The fourth replacement will only be available if a tie is level after 90 minutes and goes to extra time. There are no plans for the format to be introduced by the Scottish Professional Football League, but it could be used in next season's League Cup in Scotland. The SFA announced the extra substitute plan as Hibernian captain David Gray made the first-round draw at Edinburgh College. One preliminary-round tie remains to be played without the availability of an extra substitute after Scottish Junior Cup winners Beith Juniors and West Superleague champions Auchinleck Talbot drew 2-2 at Bellsdale Park on Saturday. Talbot host their West Superleague rivals this coming Saturday with Highland League outfit Strathspey Thistle now preparing for a journey south to face the victors. East Superleague champions Bonnyrigg Rose and North Superleague champions Banks O'Dee both face a trip to the Highlands to face Turriff United and Keith respectively. East of Scotland champions Leith Athletic host Cumbernauld Colts, who finished fourth in last season's Lowland League. Beith Juniors or Auchinleck Talbot v Strathspey Thistle BSC Glasgow v Rothes Civil Service Strollers v Hawick Royal Albert Clachnacuddin v University of Stirling Dalbeattie Star v Wick Academy Deveronvale v Gretna 2008 East Kilbride v Vale of Leithen Edinburgh University v Whitehill Welfare Forres Mechanics v Lossiemouth Fort William v Brora Rangers Gala Fairydean Rovers v Fraserburgh Girvan v Huntly Inverurie Loco Works v Buckie Thistle Keith v Bank's O'Dee Leith Athletic v Cumbernauld Colts Nairn County v Preston Athletic Selkirk v Linlithgow Rose Turriff United v Bonnyrigg Rose Ties will be played on Saturday 24 September.
summary: A fourth substitute will be available in extra time for the first time in this season's Scottish Cup.