Danielle Parhizkaran/Boston Globe Jerod Mayo’s firing was necessary … Robert Kraft said it best on Monday: he put Mayo in an untenable situation as a rookie head coach. A poor roster, an inexperienced coaching staff,

In the statement, Kraft thanked Mayo for his contributions to the team but cited the “trajectory of our team’s performances” as the reason behind his decision.

Mayo, named Bill Belichick’s successor a year ago, was fired on Sunday after the Patriots’ 23-16 win over the Bills in the regular-season finale. The former Patriots linebacker, 38, posted a 4-13 record as head coach. Kraft added Monday he “went back and forth” on the situation over the past month.