Police are appealing for information on the assault, which they believe happened in the Ashcroft Road / Lea Road area of Gainsborough between 5am and 7am on Thursday 2nd August.
The victim was treated at hospital for a broken jaw. He has since been discharged and is making a good recovery.
No other details are clear about what happened that morning, or who the offenders were.
But it is thought the victim may have approached a number of people in the Ashcroft Road / Lea Road area afterwards, asking for help.
Officers urgently want to speak to these people, as they could hold vital information.
They are also appealing to factory and shift workers in the area who may have been on their way to or from work, to get in touch if they saw anything suspicious.
Call Lincolnshire Police on 101 quoting incident number 428 of 3rd August, or call Crimestoppers anonymously on 0800 555 111.