Wonder What Roger Clemens is Worth to the Yankees?

Do you wonder why the Yankees would pay Roger Clemens the equivalent of 28 million dollars to come out of semi-retirement to pitch for them this year? Did the Yankees overpay or is Clemens worth that much money to them? This article on CNN is an attempt to quantify Clemens worth to the Yankees. The short version is, Clemens is likely to not effect the Yankees bottom line, but is likely to put them in the playoffs.