Rafael Nadal could win the next three Grand Slams says Mats Wilander

Former world number one Mats Wilander believes there is a good likelihood of Rafael Nadal coming into next year's French Open with 18 Grand Slam titles.

The Spaniard won his 15th Grand Slam title and a record 10th French Open title when he defeated Stan Wawrinka in straight sets on Sunday (11 June).

It marked a successful return to the competition after being forced to withdraw last year with a wrist injury. Wilander says the time away from the court has helped Nadal return to peak physical condition.

Since the beginning of the year, the 31-year-old has reached the finals of the Australian Open and the Mexican Open before starting an impressive winning run in the clay-court season, triumphing in Monte-Carlo, Barcelona and Madrid before his victory at Roland Garros, accumulating a 24-1 record on clay.

"Tennis players don't need to hit that many tennis balls but when they have a chance to get in the gym and work on the lower body and core that's what helps," Wilander said, as quoted on Reuters. "Nadal's flying on the court and that gives him that extra confidence."

Wilander also thinks the French Open win has restarted Nadal's campaign, having won a first major title in three years, as he predicted more Grand Slam success for the current world number two.

"I'm not that interested in the numbers...10, 11 or nine," he added. "But what this title has done is restart his campaign. He hadn't won a slam in years."

"Now he's going to be thinking going into the next three slams Novak (Djokovic) held all four. Rafa could arrive here next year in May with 18."

Nadal was set to play in the Aegon Championships next but withdrew due to fatigue.