The world No. 1's air hug routine is unfazed by the lack of fans. (Getty)

Tennis players are creatures of habit and there's no greater example of that this week than Novak Djokovic. On Monday, after his first win at the Western & Southern Open in New York over Ricardas Berankis, the world No. 1 launched into his usual celebration. It had it all: a kiss to the court, arms raised high and air hugs to all four corners of the stadium.

"Look, I'm going to keep on doing it, because I just, I don't know, I think it's part of the routine," he said in press.

The routine inside the bubble isn't so bad for Djokovic as he's staying in a private house. But in general, the daily habits from pre-match to post-match, from match to practice and from hotel to tournament site are ones that all pros are very familiar with. They're often eating the same meals, wearing the same outfits, hitting with the same partners and staying in the same hotels year over year.

But fans weren't sure how the new safety protocols might impact the energy and entertainment value in New York, where so much is at stake with so little atmosphere. When it comes to emotional reactions and exuberant celebrations, it's a good thing professional athletes naturally crave the stability of routine.

For Djokovic, there's even more behind his post-match antics.

"It's part of also me paying a tribute and a thanks to that match and to the court and to that occasion," he said. "I try to be conscious of the opportunity to play and win and everything. So that celebration also grounds me, kind of centers me and makes me aware that I have to be also grateful and share the energy with whoever is on the court."

On Tuesday, that person was Sandgren and he was the bearer of 6-2, 6-4 loss, complete with Djokovic knocking the racquet right out of his hand:

But he took the experience seemingly well:

While there are no fans allowed in Flushing Meadows for this week's Western & Southern Open as well as next week's US Open, Djokovic has his team in the stands and he directs most of his show to them, but also to everyone watching on TV.

"There is not many people, but there are a lot of people hopefully watching and that's for them, as well," he said.

Check out the latest episode of the Podcast with Tennys Sandgren: