Seau was buried on Friday, and thousands of fans attended a memorial at Qualcomm Stadium later in the day. The future Hall of Fame linebacker who played parts of 20 NFL seasons committed suicide at his Oceanside, Calif. home on May 2.
He played for the Chargers from 1990-02 and made 12 consecutive Pro Bowl appearances for his team, and will join Lance Alworth (19) and Dan Fouts (14) as the only players in franchise history to have their numbers retired.
"Junior's accomplishments on the field speak for themselves," said Chargers president Dean Spanos. "His play on the field combined with his leadership and charisma became the face of this team for more than a decade. I can't think of anyone more deserving of this honor."
In 268 career games, including 200 as a starter, Seau had 1,524 tackles, 56.5 sacks and 18 interceptions.
The Sept. 16 ceremony will include the team wearing number "55" decals on their helmets during the game and the unveiling of a number 55 banner to be hung at Qualcomm Stadium.
McCoy, the team's starting running back, is entering the final year of his contract, much like Jackson last year when he held out following the lockout.
Jackson was heavily criticized for the approach he took and he does not want the same thing to happen to McCoy. Both players are represented by agent Drew Rosenhaus.
"I think it would be in his best interest to come" to offseason practices and camp, Jackson told the Philadelphia Inquirer on Friday. "Looking back now it really hurt me more than I thought it helped me. Hopefully he saw everything I went through, and hopefully Drew won't have him go through the same thing."
The holdout affected Jackson's play and focus last season, he acknowledged.
Jackson also announced that he is hosting a free health fair in Philadelphia on Saturday, which includes vision and dental screenings, mammograms and tests for different forms of cancer. The event is through Jackson's foundation, which honors his father William, who died of pancreatic cancer.
That didn't prevent coach Jim Harbaugh from a blunt assessment when asked about his receiving crew, including first-round pick A.J. Jenkins.
"Out of shape, that's the bad news. Good news is that it's a very talented group of those young receivers," Harbaugh said. "You could tell that right away. But the bad news is we've got to get them in shape. I don't know exactly what all these guys have been doing in the last six months."
For Harbaugh, draft position and hype gets you as far as a jersey and a locker, after that, "Everybody's got the license and the opportunity." The rookies are getting introduced to the rigors of the NFL, and they'll enter the 49ers' strength and conditioning program over the next two months. Harbaugh said he wasn't surprised by the lack of top conditioning at this point – NFL standards are simply higher.
The benefit for Jenkins is that he has already graduated, so he can continue in the offseason program rather than having to wait until the end of Illinois' school year before participating in more team activities.
Harbaugh has had a chance to work with his veterans for the past few weeks, and he has been pleased with the effort and enthusiasm. That includes wide receiver Randy Moss.
"We're not a team about fueling the hype, so to speak. But Randy has been outstanding in every way," Harbaugh said. "And it's neat to watch our players watch a guy like Randy that they've watched growing up."