'Mighty Ducks' Star Shaun Weiss Says Tylor Chase Is Back on the Streets

After a promising start to getting the rehab he desperately needs, former 'Ned's Declassified' star Tylor Chase is back on the streets, TMZ has learned.

"Mighty Ducks" star Shaun Weiss tells TMZ ... Tylor was evaluated by a mental health crisis team after Jacob Harris -- the owner of Shipwreck Barbershop in Riverside, California, who has been a major advocate for Tylor -- called them. The crisis team placed Tylor in a 72-hour involuntary psychiatric hold, but they inexplicably released him, according to Shaun.

Shaun says, "They were supposed to hold him and then transport him to a detox facility that we had arranged. Instead, they let him out without contacting any of us."

According to Shaun, when Jacob found Tylor back on the street in Riverside late at night last week, the crisis team was called again. This time, they once again assessed Tylor to be a danger to himself -- Shaun tells us he was told Tylor was "smoking meth during the evaluation with no shoes or jacket in the freezing cold."

But Shaun says they still left him out on the street. Shaun also tells us ... despite some fans' well-meaning gestures to help Tylor out by giving him money on the street, that's been working against his recovery.

Shaun tells us he's not sure what to do at this point, but he's been in contact with some executive members of the Screen Actors Guild to perhaps get a political representative involved and he is calling on the county of Riverside for assistance.

Shaun works with a rehab facility called Eleven 11 Recovery in San Clemente, California, and previously told us he has a bed open for Tylor at the facility ... but legally, Tylor would have to agree to go.