Luke Mills, 29, was fleeing pursuing police officers along Church Road in Boston when he hit the boy.
The child suffered traumatic brain injury together with bruising to his lung and a fractured collar bone as a result of the incident on Sunday 2 May.
He was taken to the Queen’s Medical Centre at Nottingham where doctors placed him in an induced coma at one point.
His condition has improved enough for him to go home, but he is unable to run and suffers memory loss.
Mills was due to be sentenced this afternoon at Lincoln Crown Court but the hearing was adjourned for further evidence on the future medical prognosis for the boy.
Mills was remanded in custody and will now be sentenced next month.
Judge Simon Hirst was told that the boy has been discharged from hospital and is able to walk but cannot run.
He still has an arm in a sling due to the fractured collar bone and is suffering from memory loss.
The Judge said "This is a man who has a history of driving offences.
"I find it difficult to imagine passing any other sentence than immediate custody."
At an earlier hearing Lincoln Magistrates were told that police pulled over Mills on John Adams Way, Boston, after he was seen driving an uninsured Ford Focus.
An officer approached Mills’ vehicle and asked him to turn the engine off.
But Mills accelerated away and turned into York Street and then on to Church Road.
The officer returned to his patrol car and activated the blue lights on his vehicle as he pursued Mills.
He briefly lost sight of Mills and then came across the injured boy lying in the road. As a result the officer abandoned the pursuit and stopped to assist the boy.
The Ford Focus car was found abandoned in a field and Mills was arrested shortly afterwards.
Mills, 29, of Upsall Court, Kirton, near Boston, admitted causing serious injury while driving while disqualified as a result of the incident on 2 May this year.
He also admitted failing to stop after an accident, failing to stop for a police constable, driving without insurance and possession of cannabis.