The AP has the specifics of Nick Johnson's contract, including performance based incentives and the mutual option for 2011.

Johnson gets a $5.5 million salary next season, and the deal includes a $5.5 million mutual option with a $250,000 buyout. He can earn $1 million annually in performance bonuses: $50,000 each for 400 and 425 plate appearances, $75,000 each for 450 and 475, and $125,000 each for 500 and each additional 25 through 625. The option price would increase to $6 million with 500 plate appearances, $6.5 million with 550 and $7 million with 600. If he has at least 550 plate appearances, the buyout would be $500,000.

Johnson has reached 600 plate appearances just once in his career: with the Nationals in 2006, his finest season.

Via Mike Axisa.