Defensive back Mike Richardson, top, will miss this season because of a hand injury.

The Providence Journal / Bob Breidenbach

FOXBORO — NFL teams had until 4 p.m. yesterday to get their rosters down to 75, and the Patriots’ moves primarily involved injured players.

Wide receivers Troy Brown and Chad Jackson and cornerback Eddie Jackson were placed on the reserve/physically unable to perform list. The trio of players, all of whom are coming off knee surgeries, had been on the PUP list since training camp began last month.

The players will remain on the PUP list through at least the first six weeks of the regular season or week nine, at the latest. During that time, they can elect to open a 21-day window, allowing the player to practice. At the end of the three weeks, the players must be moved to the 53-man active roster or placed on season-ending injured reserve.

Head coach Bill Belichick was asked yesterday if the team has to decide between waiting for a player who might be ready to go four weeks into the regular season or placing him on the PUP and freeing up a needed roster spot.

“Absolutely. There are a lot of questions that nobody really knows the answer to. You just have to go on an estimate or a guess on how you feel about that situation,” said Belichick. “Sometimes there are other situations that play into them — depth on the roster, depth in another position, maybe somebody else on the team is in some type of situation where you’re questioning their availability. Those are all part of it.”

Rookie defensive back Mike Richardson was placed on season-ending injured reserve because of a hand injury. Richardson, a sixth-round draft pick out of Notre Dame, played nickel back with the first-team defense against the Panthers last Friday. After the game, he was spotted with his left arm in a sling.

The signing of designated-franchise player Asante Samuel is official. Because Samuel reported so late, New England received a roster exemption from the league, meaning it can carry 76 players for the time being.

Another rookie, offensive lineman Chris Patrick, was released. Patrick was claimed off waivers last week after having been cut by the Giants.

No news is good news

The lack of any announcements on defensive lineman Richard Seymour and tight end David Thomas, who have been on the PUP list since the start of training camp, might mean they may be ready to return to the practice field soon.

Kyle Brady’s return

Tight end Kyle Brady returned to the practice field — in pads — on Monday, and said yesterday that he was glad to be back.

“I’m feeling very good. It was refreshing and nice to be able to get back out there and get involved with the guys again and what’s going on around here. It felt good,” he said.

Brady got hurt early in training camp, and his on-field participation since then has been limited primarily to walk-throughs. He has not taken part in any of the Patriots’ three exhibition games.

The veteran was also answering questions about teammate Randy Moss, and whether the receiver is different than what Brady thought him to be based on his prior history.

“There were some things I thought were humorous. The Green Bay thing” — when Moss fake-mooned the Lambeau Field crowd as a member of the Vikings — “I thought that was funny personally. Maybe I shouldn’t say that, but I thought it was funny.”

Though questions about Moss as a teammate have dogged him, especially since his days in Oakland, Brady said the wideout is fun to have around.

“He has a great sense of humor. He calls guys out in the locker room. His personality is that he likes to clown around,” Brady said. “He’s a good guy to have around.”

Quick kicks

In addition to Samuel not being at practice, several other players were missing from the field during the early-afternoon session — Rodney Harrison, Eugene Wilson, Moss, Rashad Baker, Mike Wright, Kareem Brown and Russ Hochstein. … Belichick said in a radio interview on Monday that Moss was “close” to making a return to the field, but when pressed further yesterday on the player’s status, he said Moss is “day-to-day.”

smanza@projo.com