If you use "sprain" you have to specify the body part. Otherwise, you can just say that you generally pulled a ligament.

Can I say that I pulled tendon?

Yes, pulled A tendon

Thanks

my last link explains the difference between tendon and ligament (сухожилием и связкой)

OK, so it just means ligament. Noted! Thank you

My understanding is that a tendon can be strained too and most Russians don't know the difference either, simply saying "растянул связку" in both cases.

They do the same thing in English,
grumbler 😜