The world number four golfer Jason Day could move into the top spot with a win at this week's Masters.
The Australian has recovered from a thumb injury, but hasn't played since winning the match play world championship in February.
However, after finishing second and third in two of his three Masters starts, Day says his game suits the difficult Augusta course.
He says he hits the ball long and high which is useful approaching the fast undualting greens.
Day's compatriot Adam Scott, who won the Master's green jacket last year, could also end the week as the world number one if he can finish third or better.