The 21-year-old was taken by "unknown parties" to Aintree University Hospital, Liverpool, in the early hours of Sunday with wounds to his hand and side.
Police said he was stable and the motive for the attack was unknown, although it was thought to be targeted.
They are appealing to witnesses for information.

The 20-year-old has played three times for the Tractor Boys this term, all in the League Cup, scoring one goal.
Yorwerth, a Wales Under-21 international, joined Ipswich this summer after leaving Cardiff City.
He is eligible to make his debut for the Reds, who are currently one place off the bottom in League Two, in Tuesday's visit to Newport County.
Find all the latest football transfers on our dedicated page.
A man with stab wounds was left outside a hospital in a van with blacked-out windows, police have said.
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League Two strugglers Crawley Town have signed Ipswich Town defender Josh Yorwerth on a one-month loan deal.