MIAMI (AP) âÄî Daunte Culpepper summed up his thoughts Thursday in two words, which ushered in the start of a new era for the former Pro Bowl quarterback. âÄúFarewell NFL,âÄù he wrote. With that, a career once filled with such promise came to a most unceremonious end. Culpepper, who starred for the Minnesota Vikings before a major knee injury in 2005 curtailed his career, announced his retirement in an e-mail Thursday morning, saying heâÄôs simply grown tired of fighting for one more opportunity. The 31-year-old was the VikingsâÄô first-round draft choice in 1999, became their full-time starter a year later, and teamed with Randy Moss to pile up yards and touchdowns at an impressive rate. But he hurt his right knee in October 2005, never played for the Vikings again, and never seemed to return to his past level, either. âÄúWhen free agency began this year, I had a new sense of excitement about continuing to rebuild my career in the same way that I had rebuilt my knee after my catastrophic injury in 2005,âÄù Culpepper said. âÄúUnfortunately, what I found out was that the league did not share any of the optimism about me as an unrestricted free agent that I expected. In fact, there was an overwhelming sense that there was no room for me among this yearâÄôs group of quarterbacks.âÄù The Miami Dolphins acquired him in 2006 in exchange for a second-round pick, but Culpepper played only four games before being shut down because of continued knee problems. He was sacked 21 times in those four games, and his brief stint with Miami had two compelling images: âÄî Getting sacked seven times in his first home game, where fans booed him by halftime. âÄî Walking off the field during minicamp in June 2007 because the Dolphins wouldnâÄôt let him play, and flanked by a team security official. âÄúNow that dream to get back on the field and prove everybody wrong is behind him,âÄù said Dolphins defensive lineman Vonnie Holliday, who talked to Culpepper about his ongoing comeback quest this summer. âÄúIt has to be tough âÄ¦ When he was healthy, he was definitely one of the best.âÄù Last season, the Oakland Raiders took a shot on Culpepper, and he made five starts there, albeit only getting five touchdown passes in those games. And over the past few months, he tried to get any opportunity around the league, even saying just last week that heâÄôd be willing to be Aaron RodgersâÄô backup in Green Bay. There were no takers, and Culpepper saw no reason to keep waiting. âÄúSince I was not given a fair chance to come in and compete for a job, I would rather move on and win in other arenas of life,âÄù Culpepper said. In Minnesota, CulpepperâÄôs decision was met with disappointment, even though he hadnâÄôt played there for years. âÄúVery surprising. Surprising that he hasnâÄôt gotten a job, too. Sad,âÄù Vikings safety Darren Sharper said. âÄúLast year I didnâÄôt think he played bad in Oakland. IâÄôve seen quarterbacks that are still playing in this league today play a lot worse âÄ¦ And they still have jobs. So I donâÄôt know the reason for it.âÄù Culpepper completed 64 percent of his passes in a nine-year career, with 142 touchdowns. The 6-foot-4, 265-pounder out of Central Florida was a three-time Pro Bowl selection, and he was at his best in 2004, when he established career-highs in yards (4,717), touchdowns (39) and passing rating (110.9). Then came the knee injury, and it all went downhill from there, even though Culpepper âÄî who has served as his own agent and announced his retirement in an e-mail âÄî believes he can still compete. âÄúNo matter what I did or said, there seemed to be a unified message from teams that I was not welcome to compete for one of the many jobs that were available at the quarterback position,âÄù Culpepper said.