Dustin Johnson will seek a repeat of last year's victory in Austin ©Getty Images

Dustin Johnson will seek a successful title defence when the second World Golf Championship event of the year begins in Austin, Texas tomorrow.

It follows an opening leg in Mexico City earlier this month won by another American in Phil Mickelson.

Johnson will be one of five previous champions returning at the Austin Country Club when competition starts.

He will be joined by fellow American Matt Kuchar, the winner in 2015, and Australia's 2014 and 2016 champion Jason Day.

Northern Ireland's Rory McIlroy also returns to seek a repeat of his 2015 success while England's 2010 winner Ian Poulter completes the list.

The top 64 players in the world rankings are invited and will first participate in a round-robin stage in the matchplay tournament.

Jordan Spieth and Patrick Reed have often played together at the Ryder Cup but will be opponents this week ©Getty Images
Jordan Spieth and Patrick Reed have often played together at the Ryder Cup but will be opponents this week ©Getty Images

The most intriguing tie there consists of American team-mates Jordan Spieth and Patrick Reed, who often play together in the Ryder Cup, being drawn together in Group Four alongside China's Hao Tong Li and South Africa's Charl Schwartzel.

Sixteen group winners will progress to the elimination rounds over the weekend.

Competition is due to take place until Sunday (March 25).

Leading players not present include England's Olympic champion and world number five Justin Rose and well as seventh and eighth ranked Americans Rickie Fowler and Brooks Koepka.

United States' back-in-form star Tiger Woods has not qualified.