Releasing your calfs using muscle energy techniques (MET) I find much more specific than using rollers or a ball on your calfs. Please have a go and share if you like it or you have found it beneficial. Tight calfs can lead to shin splints, achilles problems and plantar fasciitis. It's imperative for the triathlete/ runner that the calf is kept healthy, supple and free from pain.
This video shows you a very simple but highly effective technique for pre-hab of the calf.