My understanding is that the sentence I will have played tennis. is future perfect.

But, what happens if I substitute the word "will" with a modal such as "could" or "ought to"? Does that change the tense? If so, what tense is it?

For example, what tense is the sentence I could have played tennis.?

Does a similar mechanism come into play for the sentence I will have been playing tennis. (future perfect continuous) vs. I could have been playing tennis.?