PHILADELPHIA (973espn.com) - The limited return of two key players at what has been a physical Eagles training camp was overshadowed Friday by a scary moment involving the team's top receiver, Jordan Matthews.

Matthews injured his left knee after a big hit from rookie cornerback Jalen Mills jarred a Sam Bradford pass loose. It was a low hit that had the offensive players upset and could have Mills in some hot water with the coaching staff as the veteran receiver was down for a bit before limping off the field.

Coach Doug Pederson confirmed the injury at his post-practice press conference and said Matthews is being evaluated but later told SiriusXM NFL Radio that "Everything is fine with Jordan Matthews, just going to be sore for a couple days."

That's a huge sigh of a relief for a team that is considered thin at the position with Matthews in the lineup as an amalgamation of free-agent pickups Rueben Randle and Chris Givens, along with disappointing youngsters Nelson Agholor and Josh Huff, have been rotating with the first unit as Pederson and offensive coordinator Frank Reich search for a competent three-wideout group when the team is in 11 personnel.

Matthews' setback overshadowed the fact that running back Ryan Mathews and right guard Brandon Brooks, who had yet to practice this season, were back on the field, albeit in a limited fashion.

Each took part in individual drills and but were held out of team work and Mathews' appearance turned out to be a cameo as he departed practice early, something Pederson was unaware of.

Brooks on the other hand, made it through the entire 2 1/2-hour session and was even seen working with some of the younger linemen after practice with assistant offensive line coach Eugene Chung.

"Fells good," Brooks told 973espn.com after practice when asked what it's like to be back on the practice field. "I wish I would have gotten here a little sooner but the injury prevented me from doing that. I never not want to be out here when my teammates are working."

Mathews, the team's projected starting running back, had been on the non-football injury list with an ankle injury suffered while training on his own before camp began, while Brooks tweaked his hamstring before the first practice last week.

Darren Sproles has been taking the majority of first-team reps at RB in place of Mathews, while veteran Stefen Wisniewski continued to handle the RG spot in team work.

Left tackle Jason Peters, who went down with a quad injury in practice Thursday, and safety Malcolm Jenkins, who injured his hamstring, were absent as expected.

Meanwhile, rookie running back Wendell Smallwood, also dealing with a quad, also remains out of the lineup and safety Rodney McLeod, perhaps the star of this camp from a defensive perspective was excused from practice to attend a family funeral. Starting corner Nolan Carroll was also given a veteran's day off as he deals with ankle and leg pain.

Matt Tobin handled the left tackle spot in Peters' absence while the second-team safeties, Ed Reynolds and Jaylen Watkins, were elevated to the first unit. Eric Rowe, who has been much more impressive since the pads went on, was playing in place of Carroll, an indication he has vaulted over the rookie Mills on the depth chart.

In a further sign of the more physical environment that Pederson has brought back to South Philadelphia, tight end Zach Ertz and second-team defensive end Marcus Smith were evaluated for head injuries (concussions). Ertz was cleared but Smith was concussed and will need to go through the NFL's concussion protocol before returning to the practice field.

FRIDAY NOVACARE NOTES:

-Zach Ertz, who was hit low in practice by McLeod earlier this week, and a number of other offensive players have grumbled about the low hits.

" I understand the competitiveness of the drill. But I've tried to get the message across too sometimes. We just protect each other; try not to go low if you [can]," Pederson said. "It's reactionary stuff. You know, you can't fault the players for trying to make plays."

-Backup defensive tackle Mike Martin also left early with a left knee injury.

- When asked what younger players were standing out so far in came Pederson cited the obvious in tight end Trey Burton but also mentioned undrafted free agents Paul Turner, a receiver, and Destiny Vaeao, a defensive tackle.

" I think [WR] Paul Turner has been a kid that has showed up a little bit on offense," Pederson said. "You know, even defensively, Destiny's done a nice job at the D-line position. So, there are some young guys that are giving themselves an opportunity to potentially make the roster. "

-Carson Wentz was again wearing the helmet camera as it's clear the staff wants to see how the rookie is viewing things. His best throw today was a deep post route in passing drills that found rookie receiver Cayleb Jones for a touchdown with Mills in coverage, drawing a large cheer from the season-ticket holders in attendance.

-There were two live periods today and the first put the offense inside its own five-yard line with Pederson again preferring the let the first-team offense get some confidence against the second-team defense and vice versa. The defense

The defense as a whole dominated most of the period as the offense worked the flats to get some breathing room. The biggest play was a Nigel Bradham sack on Sam Bradford that would have been a safety.

-Cody Parkey had the advantage in the kicking competition today as Caleb Sturgis hit the uprights on back-to-back kicks from 48 and 51. Sturgis hit the left upright from the left hash and the right one from the right hash. Parkey, on the other hand, was perfect all the way up to a 56-yarder when he was way short. Sturgis, on the other hand, showed the stronger leg, banging it through from 56.

In the second live period, Parkey got the only opportunity and was perfect from 45 yards.

-John McMullen covers the Eagles and the NFL for 973espn.com. You can reach him at jmcmullen44@gmail.com or on Twitter @JFMcMullen