Warner likely to enter free agency

After an all-day negotiating session at the Arizona Cardinals complex Kurt Warner's agent, Mark Bartelstein, couldn't reach an agreement.

Barring a last minute phone call, Warner will become a free agent at midnight Thursday.

Bartelstein boarded a flight Thursday evening for his home in the Chicago area, but he said he would keep in contact with the Cardinals.

Warner is hoping to land a contract around in the range of the top five quarterbacks in the NFL -- $14 million to $16 million a year. He wants a two-year deal.

The Cardinals have offered $10 million to $12 million.

Talks have been amiable. Warner said he will retire if he doesn't play for the Cardinals.

John Clayton is senior NFL writer for ESPN.com.