That looks like a fake account... Registrated after Pirog was retired, just a few random tweets, all of them are in English. I would say that is not his account.
I know he didn't live up to potential but still cool to see he's coaching now He should mentor ggg imho
Pirog is no match for GGG, there were certain rumours that GGG is exactly the reason of Pirogs retirement. It would have been a great match, but only few even on Russian forums give any advantage to Pirog.
Well couple of users, especially one who does articles on two boxing sites particularly mentioned Pirog’s unwillingness to return to ring and that one of the reasons was GGG.
There have been new discoveries in spine health. Very recently. Pirog can still come back even if not at 100%