Els opener for Donald

Both have question marks over their form after finishing the Northern Trust Open in California with final rounds of 78.

They finished 56th and 59th respectively, but while Donald, who dropped eight shots over the final 12 holes, retains top spot in the world rankings, Els - desperate to climb into the top 50 by the end of next month to qualify for the Masters - falls to 68th.

This week's event is for the game's leading 64, but the field was based on last week's ranking and Els was given a spot when Phil Mickelson confirmed he was missing the tournament to go on a family holiday.

Unless there are any further withdrawals before the draw becomes official at lunchtime Rory McIlroy will take on South African George Coetzee, called in as second reserve following Paul Casey's decision to delay his return from a dislocated shoulder.

Lee Westwood's match with Belgian Nicolas Colsaerts is set to be one of six all-European clashes.

Spaniards Sergio Garcia and Miguel Angel Jimenez are on collision course, as are Swedes Robert Karlsson and Fredrik Jacobson, Justin Rose and Paul Lawrie, Martin Laird and Alvaro Quiros and also Thomas Bjorn and Francesco Molinari.

Tiger Woods, knocked out by Bjorn in the first round at Dove Mountain last year, will be up against Spain's Gonzalo Fernandez-Castano, with the winner to face either Open champion Darren Clarke or American Nick Watney. Clarke beat Woods in the 2000 final.

Provisional draw (seeded positions in brackets):
(1) Luke Donald v (64) Ernie Els
(32) Jason Dufner v (33) Peter Hanson
(16) KJ Choi v (49) Kyle Stanley
(17) Brandt Snedeker v (48) Retief Goosen
(8) Adam Scott v (57) Robert Rock
(25) Bo Van Pelt v (40) Mark Wilson
(9) Dustin Johnson v (56) Jim Furyk
(24) Thomas Bjorn v (41) Francesco Molinari
(4) Martin Kaymer v (61) Greg Chalmers
(29) David Toms v (36) Rickie Fowler
(13) Matt Kuchar v (52) Jonathan Byrd
(20) Bubba Watson v (45) Ben Crane
(5) Steve Stricker v (60) Kevin Na
(28) Louis Oosthuizen v (37) Aaron Baddeley
(12) Graeme McDowell v (53) YE Yang
(21) Hunter Mahan v (44) Zach Johnson
(2) Rory McIlroy v (63) George Coetzee
(31) KT Kim v (34) Anders Hansen
(15) Sergio Garcia v (50) Miguel Angel Jimenez
(18) Keegan Bradley v (47) Geoff Ogilvy
(7) Jason Day v (58) Rafael Cabrera-Bello
(26) Simon Dyson v (39) John Senden
(10) Charl Schwartzel v (55) Gary Woodland
(23) Ian Poulter v (42) Bae Sang-moon
(3) Lee Westwood v (62) Nicolas Colsaerts
(30) Robert Karlsson v (35) Fredrik Jacobson
(14) Nick Watney v (51) Darren Clarke
(19) Tiger Woods v (46) Gonzalo Fernandez-Castano
(6) Webb Simpson v (59) Matteo Manassero
(27) Alvaro Quiros v (38) Martin Laird
(11) Bill Haas v (54) Ryo Ishikawa
(22) Justin Rose v (43) Paul Lawrie