Which entity is this text about?

Kurtis Eugene Warner (born June 22, 1971) is a former American football quarterback. He played for three National Football League (NFL) teams: the St. Louis Rams, the New York Giants, and the Arizona Cardinals. He was originally signed by the Green Bay Packers as an undrafted free agent in 1994 after playing college football at Northern Iowa. Warner went on to be considered the best undrafted NFL player of all time, following a 12-year career regarded as one of the greatest stories in NFL history.

Leinart was given the starting quarterback job at the start of the 2007 season. However, in the third game of the season, against the Baltimore Ravens, Warner came off the bench to relieve an ineffective Leinart during the 4th quarter with the Ravens leading 23-6 at the beginning of the period. Warner led a furious comeback, as he completed 15 of 20 passes for 258 yards and 2 touchdowns. This brought Arizona to a tie game (23-23), though Arizona would go on to lose the game 26-23 after Baltimore kicked a last-second field goal.  On September 30, 2007, during the week four game against the Pittsburgh Steelers, Warner relieved Leinart again, following another ineffective start. Warner finished with 14 completed of 21 attempts for 132 yards with one touchdown pass and no interceptions, while Leinart re-entered the game in the 4th quarter and led the Cardinals to their final touchdown. After Leinart was placed on injured reserve, Warner was named starter for the remainder of the 2007 season.  Warner passed for a career-high 484 yards against the 49ers in a 37-31 loss on November 25, but had a fumble in the end zone in overtime that was recovered by Tully Banta-Cain, and the Cardinals lost. However, the following week Warner improved; and the Cardinals earned a victory over the Browns that brought the Cardinals to 6-6 and kept them in the chase for the NFC Wild Card playoff spot. Warner finished the 2007 season with 27 passing touchdowns, just one shy of the Cardinals franchise record. Warner's performance earned him a $1 million bonus for the year, and he fell just short of attaining a 90.0+ passer rating, which would have given him an extra $500,000.
Kurt Warner