Japan's Kei Nishikori admits his number one goal in 2016 is to stay healthy enough to make a sustained push for Grand Slam glory.
Nishikori has endured a frustrating campaign over the last 11 months with a series of nagging injuries ruining his hopes of challenging for the four majors.
After making his Grand Slam breakthrough with a run to the final of the 2014 US Open, the 25-year-old came into this year tipped as the most likely challenger to the sport's big four of Novak Djokovic, Roger Federer, Andy Murray and Rafael Nadal.
But instead he was beaten in the quarter-finals of the Australian and French Opens and then pulled out of the Wimbledon second round due to a calf injury before suffering an embarrassing US Open first round defeat.
Nishikori remains certain he has the required talent and stamina to take home silverware from the Grand Slams and the Masters 1000 tournaments, but to do that he knows he must steer clear of those troublesome calf and hip complaints.
"I'm excited for next year. I think physically I have to be little more strong," Nishikori said after his season came to an end with a defeat against Federer at the ATP Tour Finals in london on Thursday.
"I try to work on little things to improve a little more. Try to be healthy, I think that's most important."
It wasn't all doom and gloom for Nishikori in 2015 as he did win three titles -- in Memphis, Barcelona and Washington -- as well as maintaining his place in the world's top eight.
For the second successive year, Nishikori qualified for the prestigious Tour Finals at the O2 Arena and he took heart from the way he recovered from an opening-match thrashing at the hands of world number one Djokovic.