A capacity field of 16 runners plus four emergencies has been declared for the Group One South Australian Derby at Morphettville.

Champion trainer Darren Weir has four runners safely in the final field with mixed fortunes following Tuesday's barrier draw for Saturday's $600,000 race over 2500m.

Chasing a third straight Derby win after Howard Be Thy Name (2016) and Volatile Mix last year, Weir will be represented by Savaheat (barrier 2), Leicester (9), Civil Disobedience (13) and Amerock (20).

Amerock will be ridden by Harry Coffey who last Saturday scored his maiden Group One win aboard the Weir-trained Sopressa in the Australasian Oaks after jumping from barrier one.

Lindsay Park will be represented by Won Won Too and Rezealient who have drawn next to each other in barriers four and five respectively while it has fourth emergency Creedence in barrier 19.

The Gai Waterhouse and Adrian Bott stable has VRC St Leger winner Runaway safely in the field with Delos the second emergency while others with multiple runners are the Mathew Ellerton and Simon Zahra stable with Into Rio and High 'N' Dry and the Trent Busuttin and Natalie Young pairing of Main Stage and third emergency Johnny Vinko.

Sydney's champion trainer Chris Waller will be represented by Australian Derby placegetter Tangled who will wear the No. 1 saddlecloth and has drawn 15.

Leicester is the $4 favourite in early markets ahead of High 'N' Dry ($6) and Tangled ($7).