The Austrian conceded Bent would be frustrated after coming off and said: "He started and wanted to show everyone that he can score goals for us and still wants to play for us.
"But obviously it is disappointing that he has picked up an injury. Hopefully he can come back fit soon. It was unfortunate for Darren that he got injured, but for me it was good that I got on and was able to score two goals.
"He congratulated me on the goals, although he couldn't get up because his leg is injured.
"You want the manager to have a headache because that is when you do well as a team."