Novak Djokovic is capable of reaching 30 grand slam titles amid his "scary" run of major success, according to Mark Philippoussis.

The Serbian is a record 23-time grand slam champion, having already won the Australian Open and French Open this year.

And Djokovic will open his Wimbledon title defence on Centre Court against Argentine Pedro Cachin on Monday as he continues his pursuit of a calendar Grand Slam.

Djokovic is looking to match Roger Federer's records of eight Wimbledon titles overall and five consecutive wins at the tournament.

His seventh title at All England Club and his fourth straight success arrived last year with a four-set win over Nick Kyrgios in the final.

Philippoussis, who lost a Wimbledon final to Federer 20 years ago, sees no signs of Djokovic slowing down.

"What is he on, 23? I mean, if he stays healthy, could he break 30? Let's see if he plays for another few years, and he gets two a year, I mean, he's getting close to that, which is scary to think," Philippoussis said to Stats Perform.

"It's incredible and not only that, he's there two hours before he practices, he warms up properly, does all the right things, he's got his team around him. 

"And [after] he finishes practising, he warms down, he's there two to three hours even after he finishes practising, again with his team, which is a strong unit. 

"He does all the right things and still doesn't take the foot off the pedal.

"He's still looking to improve in any way he can, looking for the one per cent here, one per cent there, whether it's on or off the court, or his eating, or his fitness, it really is incredible."

Philippoussis believes Djokovic, who is 36, will break every significant tennis record before his career comes to an end.

Carlos Alcaraz has emerged as a huge threat to his dominance and is looking to end his Wimbledon winning streak, but the Australian still finds it difficult to bet against Djokovic.

"Djokovic is only slightly in front of Alcaraz, but it is impossible to look past him after what he's done at the Australian Open and the French Open," Philippoussis added.

"To beat Djokovic physically and mentally in five sets, you're going to have to be on in every department and that's if you find an opening from him, which is very, very difficult to find.

"What he's continuing to do in the game and the sport is incredible.

"I don't follow all the numbers, but if he's not past everything already, by the time he's done, I think he would be leading in pretty much all of the them. 

"Maybe Jimmy Connors is still ahead as far as [ATP] tournaments won, but I believe that by the time he's done, I think he will be leading all those departments."

French Open champion Iga Swiatek is the favourite in the women’s singles, although she has never previously made it past the fourth round at Wimbledon.

Philippoussis thinks the women’s draw is far more open than on the men’s side. 

He said: "Swiatek is going to be a slight favourite but, again, grass is a different thing, it's completely different to other surfaces.

"Even though it has slowed over the years, it's still grass and you need to make those adjustments out on there. 

"You've got Rybakina, who hasn't had the best preparation, but she's definitely, as Wimbledon champion, going to have to be one of the favourites, and Sabalenka is definitely one of the favourites as well.

"But, in my opinion, I think the women’s is a little more open in the field, so I think a few girls have some opportunities."