Novak Djokovic experienced a slide on the rankings recently and it is set to continue in the next month however he still can qualify for London.
Novak Djokovic dropped a lot of points this year due to unprecedented circumstances. His Australian Open 2000 points were dropped as he was unable to take part in the event due to being deported from the country. He was not able to defend his 2000 points from Roland Garros after losing to Nadal making him drop to number 3 in the ATP Rankings
His slide continued after Wimbledon as he dropped down to number 7 because ATP stripped Wimbledon of its points due to the Russia ban. That means that Djokovic lost 2000 points from last year's edition as well. His next big chunk of points comes from the US Open where he played in the final but he will drop those points as well because he most likely won't be allowed to enter America later this year.
Overall it's a pretty big drop for Djokovic whose spot in Turin is not in danger as long as he finished between 8th and 20th in the ATP Race. It was confirmed that the winner of Wimbledon will be given that chance with Djokovic now needing only to finish in the top 20 of the Race. Seems reasonably possible.