Mara ripped his team after it ended its season with a second consecutive embarrassing loss. Mara said he was disappointed and unhappy with everyone in the organization after the Giants, who started 5-0, lost eight of their final 11 games.
Mara promised changes but said that neither coach Tom Coughlin nor general manager Jerry Reese would be fired.
Speaking to repoters, Reese asserted that wholesale changes weren't necessary.
"Well, there is work to do. But I don't think you need to blow the whole thing up," Reese said. "I still think we have a good nucleus of players here."
Mara, on the other hand, said he was angry at the team's lack of mental and physical toughness as the season progressed. He was particularly disappointed in the lack of effort over the last two weeks, especially a 41-9 Week 15 loss to the Carolina Panthers in New York's last game at Giants Stadium. Mara indicated that some coaches and players could be in jeopardy.
The Associated Press contributed to this report.