Stan Wawrinka said Novak Djokovic will not complete a calendar Grand Slam this year. Reuters/Fiona Hamilton

Novak Djokovic has been an unstoppable force in professional tennis and is bound for another great season, including a chance at completing a Grand Slam calendar this year. However, world No. 4 Stan Wawrinka predicts Djokovic will not win all four major tournaments in 2016.

Djokovic arguably played one of the best tennis in history last season and the Serb effectively carried his momentum from 2015 after winning the 2016 Australian Open in Melbourne. It was Djokovic’s 11th major title, setting him the tune for another chance at a Grand Slam sweep. However, Wawrinka is not convinced Djoker will achieve such a rare feat.

“Grand Slam? Maybe, but if I have to give a prediction, I would say no,” Wawrinka told RMC Sport. “I think that another player will win somewhere.”

Djokovic had a chance last year to complete a calendar Grand Slam, but failed to do so after suffering an upset against Wawrinka in the final round of the French Open. It was his third runner-up finish at Roland Garros in the last four years.

After another masterful showing at the Australian Open this year, the world No. 1 once again finds himself in a familiar situation ahead of the elusive French Open title.

“The French Open. It's the one I never won," Djokovic said after winning his sixth Australian Open title, reports USA Today. "Each year when I go back I feel like I'm a step closer,"

The 28-year-old Serb is set to return to action on Feb. 22 at the Dubai Tennis Championships, where he finished as a runner-up last year. According to Djokovic’s official website, his next stop would be the 2016 Davis Cup, where Serbia hosts Kazakhstan in the first round.

Meanwhile, Wawrinka is set to compete at Open 13 in Marseille, his first tournament since losing to Canada’s Milos Raonic in the fourth round of the Australian Open. The Swiss No. 2 will then join Djokovic in Dubai as Wawrinka’s final tournament this month.