Shannen Doherty's Not Too Sick For New Depo, Ex-Manager Claims

Lawyers for Shannen Doherty's ex-manager want a few more hours to grill her, and they're not buying any claims she's too sick from her cancer treatments to do it.

Steven Blatt filed docs asking for up to 4 more hours to depose Shannen in her lawsuit against his management firm, in which she accuses Blatt of mismanaging her insurance premiums.

Blatt's side already deposed Shannen for 7 hours -- the standard time allotted in California -- but that can be extended, and Blatt says his motion should be granted since Shannen's illness hasn't stopped her from partying left and right.

According to the docs, Blatt claims days before and after her first deposition, Shannen posted social media pics of herself enjoying the nightlife in NYC and Pittsburgh ... and even traveled to Australia for a fan convention.

Blatt adds she's done plenty of TV interviews too, so sitting a few more hours for questions shouldn't be a big deal.

Shannen's fired back in docs ... saying it's insulting Blatt insinuated she's not that sick, because she's living her life. She thinks the 7 hour grilling was more than enough, and says she doesn't owe Blatt any more time.

We'll see what the judge thinks.