Juan Martin del Potro has insisted that Andy Murray can become the world number one this year.
The Argentine overcame Murray in the quarter-finals of Indian Wells last week, but he has branded the Australian Open holder "a big champion".
"Murray is a big champion, he already won a Grand Slam, he made the finals in Australia and he has everything he needs to be at the top in the future," Del Potro told reporters at a press conference.
"He will be fighting for the world number one place this year and he can take a big opportunity in the grass season."
Murray is currently ranked number three in the world.
