My son told me he was using foam rollers in his training. This is what I found.
"Massage Your Muscles (AKA Self-Myofascial Release) Using a foam roller is essentially a more affordable way to give yourself a deep tissue massage. By slowing rolling over various areas of your body, you'll help break up adhesions and scar tissue and speed up the healing and recovery process after your workout."
This reminds me of the Kodokan in Judo. The Kodokan is the birthplace of Judo in Japan. It is a huge facility for practicing Judokas.
After every practice, the senior members get messages by the more junior players. It is said to have very salubrious effects upon the player's recovery.
I am sure foam rollers do something similar. I am going to give it a try.