The Hornets winger injured his anterior cruciate ligament and his meniscus in the 3-0 win over Liverpool in February.
"Gerard is improving well and there is less swelling on the knee," said Deulofeu
"He is working very well and is continuing through the stages, going slowly so we can work through the degrees of flexion in the knee.
"He will see the doctor in six weeks and decide the next step. There is a healing process for the meniscus and he needs to go slowly. After six weeks he will slowly start to do everything."