Patten, who turns 37 on Aug. 19, said he believed he could keep up physically. But it was the mental challenge that led him to tell coach Bill Belichick he was retiring after four practices.
"This is in no way, shape or form what I anticipated coming back here this year," he said. "I'm actually a little saddened that I'm proving some of the naysayers right this morning. Some felt I signed back with the team to retire, but that was not part of my thought process. I honestly felt like I could still play this game and play at a high level. I felt the competitive spirit and nature was still there, but over the course of the last two days and over the course of the break [before training camp] away from the team, there was a lot of reflection. There was a lot of contemplation.
"I just felt like it was time. It just hit me yesterday. Camp was going really well. I was still able to go out and be competitive and operate at a high level, but I believe once you get to the point in your career where it's multiple years -- it would be my 13th year -- and you're thinking about it mentally and you're not 100 percent into it mentally wise, it's tough to play this game. I always felt like when I got to that that point, it would be in my best interests to walk away."
Patten, who was out of football last season, had yet to inform his family of the decision. He said he would have preferred to walk away quietly, but wanted the chance to address the fans of New England one final time. Patten described his time with the Patriots, from 2001 to 2004, as the highlight of his career.
In a hastily arranged news conference, Patten and Belichick reflected on some memories.
Belichick said that the team had hoped to sign Patten as a free agent in 2000, which was Belichick's first year as Patriots coach. But the team lost out to the Cleveland Browns, whose offer was $50,000 richer.
The Patriots finally got their man the following season, with Patten facing what he thought were long odds for a roster spot. About two weeks into training camp, Belichick pulled Patten out of a meeting, and Patten feared the worst.
Instead, Belichick told him he had an opportunity to fight for a starting job, and that the team was offering him a three-year contract extension.
"I was thinking he was ready to release me," Patten recalled. "When you get called out of a meeting, not too much good is [usually] going on. That was the beginning to it all. Over those four years, it was just great times."
Patten played for the New York Giants (1997-99), Browns (2000), Patriots (2001-2004), Washington Redskins (2005-2006) and New Orleans Saints (2007-2008).
He totaled 324 receptions for 4,715 yards and 24 touchdowns, while adding 20 catches for 260 yards and two touchdowns in the playoffs.
One of his biggest catches came in arguably the greatest victory in franchise history, in Super Bowl XXXVI against the St. Louis Rams, when he was on the receiving end of an 8-yard touchdown pass from Tom Brady.
Saturday's news conference began with Belichick reflecting on Patten's career. He mentioned Patten's work ethic and toughness as top attributes.
"He had a tremendous career. He's meant a lot to this team," Belichick said. "Going back to '01, when we were getting this program started, the toughness, the attitude, the leadership he brought to this football team in a sort of quiet Troy Brown-like way, he just did his job and worked hard, set the pace for everybody to keep up with."
Patten was an underdog story, but his perseverance was ultimately rewarded.
"You reflect now and say, 'Hey, your career wasn't that bad for a kid, undersized out of Columbia, South Carolina and a small I-AA school [Western Carolina]. Undrafted. Working in a coffee bean factory. Electrician work. Landscaper.' Who would have thought 12 years in the National Football League?" Patten said. "Three championships. So many memories. Now I can sit back and reflect on it and pass this on to my kids."
Patten and his wife, Gailena, have four children.
Patten, who was a long shot to earn a roster spot with the team in 2010, said he has no set plans for what he will do next. He is a minister and said that will be part of his post-playing career, in addition to pursuing business interests.
Mike Reiss covers the Patriots for ESPNBoston.com. Follow him on Twitter.
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