In less than 24 hours, the New York Giants lost their most productive cornerback and leading tackler, an emerging backup cornerback and a promising second-round pick.

Cornerbacks Terrell Thomas and Brian Witherspoon both suffered season-ending torn ACL injuries and coach Tom Coughlin revealed that defensive tackle Marvin Austin will need season-ending surgery to repair his left pectoral muscle, which was injured during the Giants' 41-13 victory over the Chicago Bears on Monday.

"Obviously we are not in a great frame of mind today," Coughlin said in a conference call with reporters. "I feel badly for these guys and for our team."

Austin's injury came as a surprise and Coughlin said the 6-foot-2, 312-pounder taken in the second round out of North Carolina will have to wait until next season to play. Austin missed all of last season at North Carolina due to suspension over his alleged involvement in the NCAA agent scandal that rocked the school.

When asked if Austin's injury is a season-ending one, Coughlin replied, "Yes, I think this one is."

"Sometimes they (torn pectoral injuries) can be nurtured back to some kind of significance," Coughlin said. "But in his situation, playing where he plays and the degree of the injury -- he got caught with his arm out to the side which is the way it happens so many times -- the doctors decided that this requires surgery."

The Giants made a flurry of moves, likely in an effort to begin bringing in some healthy bodies to reinforce their thin secondary. The Giants placed Thomas on season-ending injured reserve and put Witherspoon, wide receiver Samuel Giguere and cornerback Woodny Turenne on the waived/injured list.

The Giants did add a player, signing defensive tackle Jimmy Kennedy, an eight-year veteran who has played for four teams. Kennedy was a move that was in the works before the Austin injury.

Coughlin said the team will be working out free agent cornerbacks to help a depleted secondary which lost Thomas after defensive end Jason Pierre-Paul unintentionally leg-whipped Thomas' knee as the two were pursuing Bears quarterback Jay Cutler with 22 seconds left in the first half.

The injury is significant because Thomas led the team in tackles (101) and interceptions (5) last year and was determined to have a Pro Bowl season this year.

The fourth-year cornerback, who was in the last year of his contract, was arguably having the best camp of any Giant and was a reliable part of Perry Fewell's defense.