Humberside Police, said Darren Lee Barton was assaulted outside the Rutland Arms on Saturday.
He was taken to the Diana Princess of Wales Hospital in Grimsby after the incident at about 18:00 BST, but died on Wednesday evening.
Nathan Newland, 27, appeared before Grimsby and Cleethorpes Magistrates' Court on Tuesday charged with section 20 wounding and producing cannabis.
He was remanded in custody until 22 August when he is due to appear at Grimsby Crown Court.
Police said a post-mortem examination had yet to take place to establish the cause of death.

Dozens of others remain in critical condition after the fire, apparently caused by fireworks set off by a heavy metal band.
Officials say it is possible the number of fatalities could double.
The news came as thousands marched silently through the Romanian capital in memory of the victims.
People carried flowers and lit candles at a memorial outside the nightclub.
Romanian President Klaus Iohannis has said safety regulations seem to have been ignored at the club.
The fire broke out at about 23:00 local time (21:00 GMT) on Friday at the Colectiv club, which was hosting a free rock concert by the band Goodbye to Gravity. Up to 400 people are thought to have been inside.
Survivors say the fireworks caused the ceiling and a pillar to catch fire and produce heavy smoke.
A stampede for the exit followed. More than 140 people are being treated in hospital, some with severe burns.
On Sunday officials said all of the dead had been identified.
Romania has declared three days of national mourning.

The 10-year-old son of Crown Prince Frederik was saved last Thursday by a lifeguard on the popular Gold Coast strip, 7News reports.
He was reportedly pulled from the surf at Mermaid Beach after being caught in a rip current.
The lifeguard, Nick Malcolm, was personally thanked by the Crown Prince.
Danish officials played down the incident on Monday, insisting the prince was at no point in danger.
But Stuart Keay, Mr Malcolm's supervisor, told reporters the young prince might well have died without the lifeguard's intervention.
"We got him before it got too serious but he wouldn't have come back in," Mr Keay said.
Another colleague said the lifeguard was completely unaware of the boy's identity and was not used to all the subsequent attention.
A 46-year-old man has died after he was attacked outside a pub in Grimsby.
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Two more people have died of injuries sustained in Friday's Bucharest nightclub fire, doctors say, raising the death toll in the disaster to 29.
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Prince Christian, the second in line to Denmark's throne, has been rescued after getting into trouble in the waves at an Australian beach, reports say.