Chelsea are currently making plans to bring in a new goalkeeper currently and until they sell either of Petrovic and Sanchez, I don't think they'll be bringing in anyone for now.
This deal would be doing Real Madrid more good in my opinion. Can you recall how Arizabalaga Kepa helped the Ukrainian Lunin Andriy with the penalty shoot decisions?

I feel demonstrating that showed how much value he hass to that Real Madrid side and they'll love to have him around further. At the same time, Lunin Andriy wants more game time and it's okay if he wants to leave. I'm proud of him anyways, when the likes likes of Thibaut Courtois the Belgian amd Kepa was Injured last season, he stepped out and was more than instrumental for Real Madrid. I've always wanted the swap deal between Chelsea and Napoli but look at them misbehaving. Chances of it happening slim.