After Kelvin Maynard left the field on a stretcher last time out against Derby County, Hasselbaink has confirmed the utility man will be out for the season.
"We have lost kelvin for the whole year so we will have to have a look in that area."It was unfortunate for him and for us."
Maynard looked in some discomfort after he made the tackle with Derby's Jamie Hanson.
Hasselbaink has admitted that the Dutch player was just getting over the English transition before being struck with injury.
"He has done really well in pre season and is fit.
"He was getting over the English transition.
"It is a putty but we have to move on and he has to get stronger and get back as quickly as possible."