Nadal defeated Nick Kyrgios on Sunday (8 October) to emerge victorious in Beijing for the first time since 2005, bagging his sixth title of the year in the process.
It continues what has been a stellar year for the Spaniard as he not only won a record 10th French Open title and his third US Open title, but also returned to the top of the ATP tennis rankings for the first time since 2014.
Croft, now a pundit for Sky Sports, thinks Nadal is close to his best level after going 12 games unbeaten and credited the 15-time Grand Slam winner's decision to rest at the end of 2016 and let his body heal.
"I think he's close to his best level - if not he's even improved," Croft said, as quoted in Express. "We're seeing this variety on the serve, the backhand is opening up the court and flattening out and having so much more effect on the opponents as well."
"He has to look back and think 'what a great decision it was to take time off at the end of last year and fully recover the body'. So often they don't get time to work on their game during the off-season. It really is unbelievable because many of us, I included in that, felt the game might have been moving away from him."
Croft added how Nadal's playing style compared to Roger Federer might have burdened the latter half of his career but through hard work, the 31-year-old is still flourishing with many years left in the sport.
"Federer was playing such up-tempo, serve-volley, short-point type of tennis and I wondered if we'd ever see a place for the type of tennis Nadal played throughout his career," Croft explained.
"It felt like the game was moving towards a more aggressive type of play but it shows [the] hard work he's put in, the fitness he's worked on, my goodness there's still a massive place for him.
"He'll have many years left in the game where he can keep adding those titles and maybe more Grand Slams."