The victim, whose age has not been shared yet, was found injured after the knife attack in Victoria Road, Queens Walk, yesterday (March 6) at around 4.55pm.
He was taken to hospital for treatment and remains there at this time.
No arrests have been made at this time.
Earlier this morning Victoria Road was shut both ways between Stonefield Way and Queens Walk.
The cordon has however now extended between Stonefield Way and Eastcote Lane.
A detour operation is in place for the 114 bus route as traffic is being diverted.
Anyone with information that could assist police is asked to call 101 or contact @MetCC on ‘X’ quoting CAD 5631/6Mar.
You can also provide information anonymously to the independent charity Crimestoppers on 0800 555 111.
