Concussions among major league baseball umpires have become an unfortunate by-product of the game, with a number of umpires forced into retirement due to recurring injuries. As a result, the World Umpires Association, the umpires' union, is hoping to renegotiate a clause in its collective bargaining agreement with MLB that limits disability coverage to umpires to three years, leaving a number of umpires unprotected after that until their pensions kick in. Although the umpires' current deal runs through 2010, MLB has indicated an enhancement in the disability coverage could be agreed upon before then.
See "Home-plate umpires find themselves in the line of fire", Paul White, USA Today, June 18, 2008