Lincolnshire Police are appealing for witnesses to an attack in Grantham on October 1.
The assault took place at around 3.30pm.
The victim was walking along Brook Street in Grantham, close to the junction with North Street, when the offender blocked his path.
Whilst attempting to walk away the victim believes he was then kicked, resulting in serious injury.
The offender is described as white, 5’4″, with short black hair. He is believed to have been wearing a black anorak and hoody.
Police called for any witnesses or drivers with dash cam footage taken in the area around 3.30pm to call 101, quoting incident number 398 of October 1.