The transfer window is now open and Celtic will be keen to put their best foot forward in negotiations to get players through the door over the coming weeks. Several areas need to be addressed ahead of the new campaign by Brendan Rodgers; nevertheless, there are also internal matters requiring a solution before too long. According to reports, Watford are the latest club to open talks with Celtic youngster Rocco Vata amid his contract being set to expire at Parkhead, though he still has an offer on the table from the Hoops to extend his stay. Daniel Kelly will be available on a free transfer at…