Per WEEI via PFW, as reported by Christopher Price: Report: Brady has tennis elbow Tennis elbow represents a more serious issue than a bone bruise. For those of you who are not familiar, tennis elbow is an overuse injury occurring in the lateral side of the elbow (inflammation of the tendons on the outside of the elbow), that is caused by overrepetition (e.g., hitting tennis balls thousands of times) resulting in tiny tears in the forearm tendon attachment at the elbow. For Brady, it's most probably a result of him throwing the ball so much. The problem with tennis elbow for Brady is that pain comes through torquing the elbow and wrist muscles and also with the grip (e.g., grasping something), and those two are very integral to a throughout throwing motion with the football. For me, it makes a lot of sense because I haven't been seeing a lot of throws that have tight spirals on them. It also explains why a lot of his throws have fallen short of the mark. Surgery is not usually required, but this is not an issue that is easily overcome. While it is not disabling, it sometimes ends up as a life-long issue.