Top four kept apart in Match Play
Casey has been out of action since early August with a torn rib muscle
The top four players on the European Tour money list have avoided each other in the draw for this week's World Match Play Championship in Spain.
Lee Westwood, Martin Kaymer, Rory McIlroy and Paul Casey have all been drawn in different groups for the tournament's new round-robin stage.
Westwood's four-man group includes fellow Englishman Ross Fisher while Casey's features American Anthony Kim.
The group winners at Finca Cortesin progress to Saturday's semi-finals.
Masters champion Angela Cabrera of Argentina, Sweden's world number seven Henrik Stenson and Colombian Camilo Villegas are also in the field.
The round-robin ties see every player matched up against every other competitor in their group during Thursday and Friday.
Casey, Northern Ireland's McIlroy and Germany's Kaymer all have the chance to take the European number one spot from Westwood should they make the semi-finals.

