The Denver Broncos were without WR Brandon Marshall and several other key veterans during a morning practice session on Monday, while Terrell Suggs, Jon Beason and others also missed training camp practices around the league.

While Antonio Pierce was on the field taking part in the first training camp practice with New York Giants on Monday, a NYC grand jury was deliberating his role in the weapons charges brought against ex-teammate Plaxico Burress.

New York Giants star linebacker Antonio Pierce, who testified for two days before a grand jury last week, will not be indicted, according to a source with knowledge of the situation.

A few thoughts and observations from Baltimore’s training camp.

HOUSTON — Running back Steve Slaton, who emerged as a surprise rookie sensation in 2008 after joining the Texans as a third-round draft pick from West Virginia, is showing every bit of the tremendous rushing and receiving skills in practice that he displayed last season.

On days such as Sunday and today, when the Texans have a contact practice in the morning, players are out of pads for a walk-through session in the afternoon. Gary Kubiak believes staging the walk-through later in the day enhances the ability of the coaching staff to teach while correcting mistakes made in the morning and working on finer points.

Pro Bowl linebacker Terrell Suggs is sitting out the Baltimore Ravens’ morning practice after “tweaking” his ankle in Sunday’s practice, according to a team source.

The additions of free agents with NFL starting experience, Dan Orlovsky and Rex Grossman, are providing encouragement that the Texans can stay on track even if Matt Schaub doesn’t play.

Two players expected to be key members of the Eagles defense this season — LB Stewart Bradley and CB Ellis Hobbs — left practice Sunday with injuries.

Bradley left with a knee injury, while Hobbs suffered a stinger. Both players will be reevaluated following MRI tests scheduled for Monday.

The Titans placed rookie WR Kenny Britt on the physically unable to perform list, just one day after the first-round draft pick signed a five-year, $12.25 million contract.

Britt reportedly is still recovering from a hamstring injury that the Titans medical staff wants to let rest for a few more days. Coach Jeff Fisher said Britt could begin practicing by the middle of the week and in time to play in next weekend’s Hall of Fame Game against the Buffalo Bills.

The Jaguars and first-round draft pick Eugene Monroe have yet to reach a contract agreement, but the team is hoping to avoid a repeat of last year, when No. 8 overall selection Derrick Harvey missed 33 days of training camp during the longest holdout in franchise history.

Vikings coach Brad Childress said Tarvaris Jackson stayed inside Sunday to receive treatment on his sprained left knee, which is expected to sideline the quarterback until sometime next week. Childress also said the team doesn’t plan to sign another QB.

Browns coach Eric Mangini sais he has no intention of rotating QBs Brady Quinn and Derek Anderson once he names a starter later in the preseason.

“Once you make that decision and go with that decision, then at that point you’re moving forward with that group,” Mangini said.

The real pressure point of the first round is coming in the second quarter, with picks 8 through 12 all unsigned to this point. That span includes the player who has been absent from his camp the longest thus far — defensive end Aaron Maybin has missed the Bills’ first week of practice. It also includes a wide receiver who many believed would go in the top five (Michael Crabtree of the 49ers) and the first running back selected in the draft (Knowshon Moreno of the Broncos).

Broncos WR Brandon Marshall limped off the practice field Sunday with an apparent hamstring injury.

Marshall, who has openly requested a trade, is also coming off offseason hip surgery.