The young man was stabbed in Dudley High Street in the early hours of Sunday morning and taken to hospital where he remains in a critical condition.
Two men aged 25, a 22-year-old and an 18-year-old, were arrested in Northamptonshire on suspicion of grievous bodily harm, and remain in police custody.
A section of the High Street was closed between Vicar Street and Stone Street but has since reopened.
West Midlands Police said a review of CCTV footage is under way and officers remain in the area carrying out further enquiries and offering reassurance to the community.
The force has said it would encourage anyone with CCTV, mobile phone or dashcam footage to get in touch via its website, quoting log 518 of 29 January.