Take a look at this page from SKA's website. It is a team roster and it says it was updated "as of 7.8.13". Notice Ponikarvosky's name is on the roser, official team head shot and all. This indicates to me that he most likely signed with the KHL team in July (notice Kovalchuk's name is not yet on this roster, he signed after July 8th"). Why was Poni's signing not announced then here until last week?
http://en.khl.ru/clubs/ska