Ok, so Chelsea have a mystery signing who will be unveiled in early July (as first reported by emo in all transfer rumours)

Who do you guys think will be Chelseas surprise signing on July 1?

I'm tempted to say it's Lukaku. He seems certain to leave and Everton have already gone and spent big, perhaps with the money from the transfer. Also, Lukaku has always wanted to play for Chelsea and Conte could have sent the message to Costa as he knew the Lukaku deal was done. The reason they were keeping it a secret for now is because they wanted it to seem like Costa was still needed by the club, so they could negotiate a high selling price for him. Also, because it's such a big signing they want to unveil it properly.
The only reason it might not be him is the apparent row between Conte and the board over spending power and lack of signings. However, the row could actually more be because of the infamous text.

Other contenders?
It could be Bakayoko, Cabellero or someone we never expected!

Have never seen him play actually, so can't really say something about him

@JuanMata Watched a video of him just a moment ago and he seem very decent . From what I heard, he is solid in defense and from what I seen, he is fast, is an excellent dribbler and as a good vision. He is 23 as well so I think so could even improve. Barca are targeting him and some people compared his playstyle to Dani Alves. Only problem is that I'm not sure if he would be physical enough to play lots of match in the PL. :S