Both players were linked with moves to west London this past summer but opted to remain in Italy, and according to Italian daily Corriere dello Sport (h/t TalkSport), both are now on the brink of signing extensions.
Chelsea manager and former Juve chief Antonio Conte has signed the likes of Marcos Alonso, Antonio Rudiger and Davide Zappacosta from Serie A teams since arriving in England.
However, Chiellini in particular would be difficult to pull away from the Old Lady considering he's now in his 13th Juventus season and has grown to become almost synonymous with their brand, per OptaPaolo:
2010 - This is the first time since April 2010 Juventus play without anyone of Buffon, Barzagli, Bonucci, Chiellini in Serie A. Innovation.2017-9-9 16:00:34
Sandro arrived in Turin 10 years after his Italian team-mate but has swiftly developed into a crucial part of manager Massimiliano Allegri's setup, a piece of the puzzle Juve understandably want to keep their hands on.
Juventus defeated Olympiakos 2-0 on Wednesday in what was their first win of the UEFA Champions League season, and even at 33 years of age, Chiellini impressed as a member of their defence:
Squawka Football @Squawka
Only two players completed 100+ passes in the Champions League this week: Andrea Barzagli (105) Giorgio Chiellini (101) ⚫️⚪️ https://t.co/REaGj9juTs2017-9-28 09:31:44
According to Corriere dello Sport, Chiellini—who is in the final year of his current commitment—is set to sign a new contract until the summer of 2020, while it's suggested Sandro is on the verge of agreeing a two-year extension.
Should news of Chiellini's contract prove true, it would keep him in Turin until the age of 36, while any hopes Chelsea might have of landing Brazil international Sandro would be severely stunted, at least for the time being.
Goal's Nizaar Kinsella reported on Chelsea interest in Sandro over the summer, at which point it was clear the Bianconeri wouldn't be tempted into losing another key portion of their defence:
Nizaar Kinsella @NizaarKinsella
Alex Sandro - Juventus reject approaches due to Bonucci sale Danilo - Outbid by Man City Oxlade-Chamberlain - chose Liv/quit being a WB #CFC2017-8-30 19:26:49
The Italian could be ready to reinforce his back line again next summer in the next step of his Chelsea project, although it doesn't seem he'll be able to rely upon old club Juve for aid.