Can these wool flannel trousers be worn casually?

I often see people on here talking about wearing grey flannel trousers casually but I have difficulty making it work. The pair I have just seem too formal and "suit like" (even though they aren't part of a suit). I actually bought them to wear with sports jackets back when I had a need to dress smart for work. Now I'm wondering if I can repurpose then as a smart jeans alternative or are they just too formal?