It depends on the extent of the damage. A torn tendon has a good chance of healing. If only a minor tear, it should recover of its own accord. In my case, they weren't torn. They had both separated totally from the bone. There was no chance that they would recover. It was necessary to insert hooks into the bone, pull the tendons outwards and attach them to the hooks, then stitch them down. The final link was made by scar tissue. I'm told that mechanically, all is as it should be (joint, bones, tendons, muscles etc), but it will take time (talking months here) for it all to function as it should.
So for 5aday, a lot depends on how badly damaged the tendon is, and the specialist's opinion as to the likely recovery.