Naturally , the nature of the injury and limits of the ROM is not explained. Tendon. joint socket, actual muscle fiber, bone,ligament, etc, all limited guess work as to how much stress can be applied in a leg exercise.
If leg presses (machine angle/ROM) present no problems, with the back supported, than might try leg extensions (machine) first and the mentioned leg press. Prefer exercises be preformed one leg at a time. Insuring a balance of strength and muscle influence on the weak and normal leg. With one leg at a time you can make different weight selections for either leg, if that is needed. The injured one may require less weight.
Add leg bicep leg work, which can be very important in rehabbing a injured leg/knee. Most people forget that part of recovery. Would usually advise light stretching and massage/lotions, but in your case I really don't know the grade of you problem with the knee. Good Luck.