Leeds United could start the season without Luciano Becchio and Davide Somma, two of their main strikers.
Argentine Becchio may need an operation on a ruptured tendon while South African Somma will be out for six to nine months with a cruciate injury.
Manager Simon Grayson told the club website: "We're just weighing things up with Luc now and whether or not he needs an operation.
"We'll know more over the next few days in terms of which way we will go."
Becchio, 27, scored 20 goals last season but missed the end of the campaign with a hamstring problem.
"We let things settle down over the summer after the injury last season and he did some light training when we came back, but he's got a ruptured tendon and we have to consider things now," the Leeds manager said.
Grayson is already facing up to the prospect of missing Somma for the majority of the season after the South Africa international picked up a serious knee injury in pre-season training.
"We're obviously hugely disappointed Dave's sustained this injury," the manager said.
"You could say six to nine months to recover from something like this. It'll take a couple of weeks for the swelling to come down then he'll have the operation to put it back in place.
"Andy O'Brien still has his side strain as well, hopefully we won't be too long without him but it's a delicate muscle.
"He'll be touch and go, but hopefully could be back early next week in terms of light training.
"It's been frustrating for all of them. Andy has worked hard over pre-season, Dave's was innocuous, and Luciano had the injury at the back end of last season and has done some work with us."
Grayson banned his players from using Twitter this week after Somma revealed details about his injury on the social networking website.