The Arizona Cardinals signed quarterback Kurt Warner to a one-year, $4 million contract prior to the 2005 season, and when the year was over he had put together a rather unimpressive resume with the team.
Two wins, eight losses, 11 touchdown passes, nine interceptions and nine fumbles. Warner was beset by injury and replaced by Josh McCown, too, though he regained the starting job late in the year.
The Cardinals and Warner agreed to a three-year contract extension after that, but the veteran was expected to be little more than a caretaker at best, but more likely a clipboard holder for the team's next, younger QB.
Arizona drafted USC QB Matt Leinart with the 11th pick in the draft that April, and four games into the 2006 season Warner's time as a starting quarterback appeared to have ended, as he was replaced by the former Heisman Trophy winner during a loss to the Atlanta Falcons.
No one could have predicted where Warner's career would go from there, just like not one person would have expected his name to ever be on a list of the best 20 free agent signings in NFL history. Yet, that's exactly what happened, as NFL.com ranked Warner to the Cardinals fourth.
After orchestrating the rise of the "Greatest Show on Turf" in St. Louis, Warner helped another woebegone franchise emerge as a contender. Warner led the Cardinals -- a franchise that had gone 60 years between championship games -- to an unlikely Super Bowl appearance. Three of the Cardinals' four home playoff games in team history came with Warner behind center, and each of those three games resulted in an Arizona victory.
After throwing just 17 touchdown passes in his first two years with the team, Warner went on to toss 83 over the next three. He passed for 11,753 yards and tallied a QB rating of 93.6. Warner led the Cardinals to a pair of NFC West titles as well as Super Bowl XLIII, and cemented his Hall of Fame status in the process.
So yeah, it's fair to say he turned out to be one of the best free agent signings of all time, even though that didn't look to be the case early on.
And for the record, Warner trails only Deion Sanders, Drew Brees and Reggie White on the list.