The man, in his 50s, took himself to hospital on Monday morning after the shooting which is believed to have happened near a canal in Brownhills.
His injuries are described as "not life-threatening or life-changing" but he remained in hospital for further treatment on Tuesday.
West Midlands Police searched a stretch of the canal near High Streets in Brownhills on Monday as part of a probe.
The force said it was still working to establish where the shooting took place.
A spokesman for the force said: "We are investigating after a man in his 50s attended hospital with a gunshot injury yesterday morning.
"His injuries are not believed to be life-threatening or life-changing. He remains in hospital for further treatment today.
"A stretch of canal off High Street, Brownhills, was searched by officers yesterday as we work to establish where the shooting took place.
"Anyone with information can contact us via live chat at west-midlands.police.uk. Please quote log number 764 of 9 August.
"Alternatively you can speak anonymously to Crimestoppers on 0800 555 111, or contact us on 101."