Schalke aim to close the signing of Manchester City winger Rabbi Matondo today.
The Wales international is in Germany and passed a Schalke medical on Tuesday.
BILD says the Germans had expected to sign Matondo yesterday - and were surprised by City delaying the required paperwork.
However, everything will go through this morning - which will include a buy-back clause for City.
Matondo will sign with S04 for a fee rising to €10m, with City having a buy-back option set at €55m.