Ezekiel Williams -- a semi-professional soccer player in England -- is dead ... and cops think foul play may be involved ... because they're investigating this as a possible murder.

The BBC reports a homicide investigation has been opened into the footballer's death after he sustained injuries in the town of Milton Keynes -- about 50 miles from London -- on Sunday ... he was hospitalized and died from his injuries.

Two men have been arrested on suspicion of murder, the BBC reports ... while another was arrested for suspicion of assisting an offender.

Hendon F.C. -- the semi-pro club for which Ezekiel started playing in September -- released a statement about his shocking death ... remembering him as a "humble, unassuming and generous individual with a razor-sharp wit."

A GoFundMe has been posted online to raise money for his wife and kids. The caption for the fundraiser states he "had the purest of hearts, if you ever encountered Ezekiel, you would have heard his words of encouragement and felt his infectious positivity. A man who never had anything given to him and was prepared to put in the work to achieve his full potential!”

Ezekiel was 26.

RIP