It's not tiredness. It's out-of-form. It's expected.
He had a sensational first half of the season with Genoa, sensational first couple months with us. Look at the rest of the team and how they performed also, it's no wonder Piatek has struggled. We look lost on the pitch more often than not because there's no tactical setup going forward. It's cross into the box to a single man.
The last game out against Fiore was different in that we tried to overload the box with 2-3 players which was much better, and he happened to miss a free header. Shit happens, but definitely not being sold. He can become world-class.