Ronnie O'Sullivan will begin the defence of his Betfair World Championship title against Scotland's Marcus Campbell.

O'Sullivan was initially slated to miss the competition at the Crucible in Sheffield, pulling out of the rest of the 2012-13 season last November due to "personal issues", but he ended his sabbatical in February.

He will be chasing a fifth world title and, despite a significant time away from the game, the 37-year-old will be confident of defeating Campbell, whose best result came when he defeated Stephen Hendry 9-0 in the 1998 UK Championship.

World number one Mark Selby is perhaps the favourite heading into this event having triumphed in the Masters and the UK Championship this season and will open his campaign against Crucible debutant Matthew Selt, who defeated 1997 champion Ken Doherty in the final qualifying round to earn his place in the main draw.

Alan McManus yesterday ended his seven-year wait for a return to the tournament although the Scot, who is a two-time semi-finalist in Sheffield, will be the underdog against Chinese number one Ding Junhui.

Like McManus, Jimmy White was aiming to play in the competition for the first time since 2006 but his hopes were yesterday ended by Robert Milkins, who will face 2010 champion Neil Robertson.

Four-time champion John Higgins has had a forgettable season, winning just the Shanghai Masters so far this season, and he has been given a tricky opponent in the first round, with Mark Davis proving his worth by reaching the semi-finals of last year's UK Championship.

Former world number one Judd Trump may also have been wishing for a slightly easier draw after being paired with Dominic Dale, while former champions Graeme Dott and Peter Ebdon will face each other.

Shaun Murphy, champion in 2005, has reached three ranking semi-finals this season and he will start against Martin Gould, Matthew Stevens and Marco Fu will square off, while outspoken world number six Mark Allen meets Mark King.

The tournament gets under way this Saturday, with the final to be played on May 5 and 6.

Draw for the first round:

Judd Trump v Dominic Dale
Mark Williams v Michael White
John Higgins v Mark Davis
Barry Hawkins v Jack Lisowski
Stuart Bingham v Sam Baird
Matthew Stevens v Marco Fu
Ali Carter v Ben Woollaston
Neil Robertson v Robert Milkins
Mark Selby v Matthew Selt
Ricky Walden v Michael Holt
Ronnie O'Sullivan v Marcus Campbell
Shaun Murphy v Martin Gould
Ding Junhui v Alan McManus
Steven Maguire v Dechawat Poomjaeng
Graeme Dott v Peter Ebdon
Mark Allen v Mark King