Thames Valley Police has opened a murder investigation into the death of footballer Ezekiel Williams, aged 26.
The inquiry followed an assault in Milton Keynes, which resulted in two men being arrested on suspicion of murder.
A third man was arrested on suspicion of assisting an offender.
The suspects, aged 21, 28 and 30, are all from Luton and remain in custody.
South Central Ambulance Service notified officers shortly after 1.50am on Sunday, November 1, after receiving reports of an assault on Midsummer Boulevard.
Williams suffered serious injuries and died in hospital on Monday.
He was formally identified, and specialist liaison officers are supporting his family.
The Major Crime Unit is directing the investigation under Detective Inspector Rob Underhill.
Police said there was no perceived wider danger to the community.
Police also plan a higher presence around The Hub and the Milton Keynes city centre during the coming days.
Underhill said the force’s priority was to support Williams’s family and loved ones.
Specially trained liaison staff are helping relatives cope with their loss.
Williams played in midfield for Hendon FC in north west London and joined the side in September.
Following his death, the club described him as hard-working and selfless and postponed its London Senior Cup match as a mark of respect.
A memorial fundraiser was also launched, characterising him as humble and family-oriented and saying he took pride in helping others.
Police have appealed for people who were near Midsummer Boulevard or The Hub from 1am until 2am on Sunday to provide information.
Officers are especially interested in cellphone video, dashcam images and CCTV recordings from that period.
Reports can be made by calling 101 or online, with reference 43260570882 given.
Anonymous information may be supplied to Crimestoppers on 0800 555 111 or via its website.