Wolfsburg's Portuguese international midfielder Vieirinha is set to be out of action for at least a month after rupturing knee ligaments during his side's German Cup victory over Aalen on Tuesday.
"It's cruel for him and for us," bemoaned club sporting director Klaus Allofs on Wednesday. "We all wish him a speedy recovery and will do everything possible to help with the rehabilitation."
A decision on when the 27-year-old will undergo surgery will be taken later in the week as a 2-0 win over second division Aalen was stained when he went down injured in the 31st minute.
"It's a very difficult moment but I know my family, my team-mates and our supporters will give me the support to come back quickly," said Vieirinha.
The offensive midfielder, who came up through the Porto youth system before making his mark in Greece with PAOK, had played in all six Bundesliga matches this season and scored his first goal during the 4-0 rout of Schalke on matchday two.
The club are sixth in the table with three wins and three defeats as they prepare for a difficult trip to champions Bayern Munich on Saturday.