Consider a case where we have a master key MS that is used in pseudo-random function to generate a set of pseudo-random values. Then we use key derivation function to derive a key from each of pseudo-random values. Assume all the keys are long enough (in security context).
Question: In the above scenario can I use the keys derived from the pseudo-random values (or the derived keys) as a encryption key or a key for pseudo-random function?
In other words, is there any situation where we should not consider a derived key as an actual random key?