There's no easing back in for Jason Day when he returns to tour golf action this week from his extended three-month layoff.
Coming off arguably the greatest season in Australian golf history, Day hasn't played a tournament since the Tour Championship in September as he took a lengthy break while welcoming the birth of second child Lucy in November.
But he will head straight back into battle with Jordan Spieth for golf's No.1 ranking in the Tournament of Champions in Hawaii.
No.1 Spieth and No.2 Day head the 32-man field comprising winners of US PGA Tour events in 2015 in the $A8.1 million event at the Plantation Course at Kapalua on Maui starting on Friday.
Joining them are fellow top-10 players Bubba Watson, Ricky Fowler, Dustin Johnson and defending champion Patrick Reed plus British Open Champion Zach Johnson.
The golf world waits to see how 28-year-old Day and 22-year-old Spieth fare in backing up their fabulous 2015 seasons.
Both men won five times, with Spieth claiming two majors (Masters and US Open) to Day's maiden one (US PGA Championship).
But Day finished the season stronger as they traded the No.1 ranking, winning four of his last seven tournaments - the Canadian Open, PGA Championship, The Barclays and the BMW Championship - to finish with $US9,403,330 ($A12.89 million) in prizemoney.
He also has a good record in the Tournament of Champions, having surged home with a course record-equalling 62 last year to tie for third after being tied ninth in his other appearance in 2011.
Day and Spieth will be looking for a fast start to the year with a fit-again world No.3 Rory McIlroy expected to press his claims for a return to No.1 ahead of the first major championship showdown of the year at the Masters in April.