Borussia Dortmund chief executive Hans-Joachim Watzke has revealed Manchester United have made an improved offer for Henrikh Mkhitaryan.
The Armenian netted 23 goals for Dortmund in 2015-16 and was voted the Bundesliga Players' Player of the Season.
Watzke told Kicker on Monday that he wanted the situation to be clarified by the time pre-season training began on Monday, a point he has reiterated.
An agreement over a £26.3million fee to take Mkhitaryan to Old Trafford was thought to have been agreed.
However, the Dortmund CEO admitted United have raised their bid, with a £33m offer now reportedly on the table.
"We have to evaluate this as we start our pre-season training on Monday, and we will do that at the weekend," Watzke told WAZ.
"The situation has changed - Manchester United improved their offer.
"In situations like this you have to see such a decision from different points of view and in the end we will make a decision.
"I have contacted the relevant people and we will decide at the weekend.
"We need the opinions of different people and after that the board of directors will decide."