Borussia Dortmund are close to signing French forward Pierre-Emerick Aubameyang from Saint-Etienne.
The Bundesliga club's sporting director Michael Zorc confirmed they are in negotiations with the Gabon international and hinted that a deal may not be too far away.
"We are very far with Pierre-Emerick Aubameyang, but we seal deals after the final signature. We still need some time, but I am optimistic that it can go fast right now," Zorc said.
"The rest will be decided in the next days and weeks."
Dortmund have only signed one player in the close season, Sokratis Papastathopoulos, while they also lost influential midfielder Mario Goetze to Bayern Munich.
However, manager Juergen Klopp wants to take time to strengthen his squad and urged patience.
"We know how we want to play football in the new year, we know our goals," he said.
"We can’t achieve everything on the first day, we will take the time that is necessary.
"We are very pleased with the team we have so far. There are no differences (to the preparation last year) but that doesn’t matter, because I rate all differently."
CEO Hans-Joachim Watzke also revealed the club want to qualify for the UEFA Champions League again after their run to the final last term and improve their showing in the DFB-Pokal.