IRVING, Texas -- At the end of the disastrous 2010 season two of the Cowboys biggest problem areas were the secondary and offensive line. A year later, they remain problem areas but this time the Cowboys will do something they hope rectifies the problems.

In addition to the expected changeover in personnel in 2012, the Cowboys will have a change in assistant coaches, too, with Bill Callahan and Jerome Henderson replacing Hudson Houck and Dave Campo.

The changes had to be difficult on Jason Garrett because of his personal relationships with Houck and Campo that go back to his playing days with the Cowboys.

But at some point you have to cut the cord.

By not renewing the deals for Houck and Campo, Garrett severed ties to the teams Super Bowl teams of the 1990s and brought in two coaches with no real ties to his playing or coaching days.

It takes some guts to go with guys you know only on reputation or on the recommendations of others.

Callahan has an excellent reputation as an offensive line coach. Henderson, who played for Bill Parcells with New England and the New York Jets, was on the Cowboys’ wish last year but Cleveland blocked the move. He was the only defensive assistant to remain under new coach Pat Shurmur’s staff.

Why did these moves happen today?

Tuesday marked the end of the seven-day grace period teams have in attempting to keep coaches whose contracts had run out after the 2011 season.

Callahan reportedly turned down an extension from the New York Jets, where he was the assistant head coach. What will be his title with the Cowboys? Does he come in solely as the offensive line coach or does he take over the running game coordinator title Houck had as well?

Henderson should take over a secondary in transition. Terence Newman could be a salary-cap casualty. Abram Elam, whom he coached in Cleveland, will be an unrestricted free agent, as will backup cornerbacks Alan Ball and Frank Walker. The Cowboys re-signed cornerback Orlando Scandrick and safety Gerald Sensabaugh to extensions in 2011 and cornerback Mike Jenkins will be in the final year of his contract in 2012.

Maybe the moves came a year too late, but better late than never.