A Philadelphia man admitted he tried to extort money from New York Giants head coach Tom Coughlin by mailing letters in which he threatened his family.

Herbert Alex Simpson, 30, pleaded guilty Monday to two counts of sending threatening communications to Coughlin and one of Simpson's former employers, the Department of Justice said.

Simpson pretended to be other people in the letters, telling Coughlin that his "life would be a living hell by doing something to [his] family," according to the DOJ.

In correspondence to his ex-boss, Simpson threatened to kill him and his family.

Simpson faces up to 10 years in prison and more than $500,000 in fines when he's sentenced Feb. 26, the Justice Department said.