Ben Shelton

Based on the provided news articles, Ben Shelton is not mentioned. The articles focus on Novak Djokovic's advancement to the Australian Open semifinals after Lorenzo Musetti retired due to injury. Djokovic described himself as "extremely lucky" to progress, highlighting the close nature of the match before Musetti's injury. The articles also mention Jannik Sinner. Therefore, without additional information, it's impossible to provide any details about Ben Shelton's current relevance or significance based on these specific articles.