Sandro was on the Blues’ radar over the summer, as Antonio Conte wanted to provide competition for Marcos Alonso.
A number of bids were rejected, as Juve held firm over the Brazilian.
Sanchez meanwhile, looks increasingly likely to leave the Emirates at the end of the season as he will be out of contract and has cut a frustrated figure at times this campaign.
Reports have suggested United are still interested, but they accept Manchester City are more likely to clinch a deal for the Chilean.
Conte over the summer was left furious after missing out on a number of key targets, including Romelu Lukaku who joined Manchester United from Everton.
And according to the Daily Mirror, the Blues are ready to make a fresh move for £60million-rated Sandro as well as Sanchez.
The report suggests the west London outfit want to show ambition in the January window so as to keep Conte on side.
The Italian tactician has found himself linked with the AC Milan job, with Vincenzo Montella going through a tough spell at the moment with the Serie A outfit.
And by making a splash in January, it is hoped that Conte who opted for a big pay rise instead of a contract extension, could be persuaded to stay at Stamford Bridge.
Conte hinted at the end of last month that he would be open to managing in his homeland again.
He said: “I have nostalgia for Italy. I did not have it in my head to stay abroad for so long.
“Once I have had some more nice experiences I will return to Italy, for sure.
“I don’t know when, but the goal is to do that.”
