PHILADELPHIA (973espn.com) - The Eagles took a significant hit on the injury front Thursday as two of the team's best players, left tackle Jason Peters and safety Malcolm Jenkins, failed to finish the three-hour session.

The aging Peters injured his quad during the first team period of the practice and dropped to the ground before walking off to sideline to receive attention from the training staff, while Jenkins reached down and grabbed the back of his leg (indicating a hamstring) after checking receiver Jordan Matthews during one of the drills.

Both players eventually retreated to the inside of the NovaCare Complex long before the marathon session ended.

Matt Tobin replaced Peters at left tackle and Ed Reynolds got a lot of first-team reps next to Rodney McLeod on the back end of the defense.

"When a guy goes down, it's a great opportunity for those other guys to step up," defensive coordinator Jim Schwartz said after practice. "The opportunity only exists if you take advantage of it, and those guys need to do a better job of taking advantage of it."

The Peters injury is a major concern because the 34-year-old dealt with a quad problem last season that was related to a disc problem in his back.

The two veteran Pro Bowlers join an injury list that already includes running backs Ryan Mathews and Wendell Smallwood, along with undrafted rookie wide receiver Marcus Johnson and starting right guard Brandon Brooks. Mathews (ankle) and Brooks (hamstring) have yet to practice in camp so far.

THURSDAY NOVACARE NOTES:

-Sam Bradford had his sharpest day to date, throwing the football with amazing accuracy and alacrity, almost at a Green Bay-preseason level. The problem with Sam is consistency from day to day and it remains to be seen if you can build on what was an outstanding performance.

-Carson Wentz was wearing the helmet camera again on Thursday and the coaching staff will likely look at that footage and see a quarterback who is a tad late in his throws. The speed of the pro game is an adjustment every young QB must make and it's still a work in progress for the No. 2 overall pick. Wentz's best throw of the morning was a nice pump-and-go to Nelson Agholor and the rookie also has a real nice touch on fade patterns. The problems start when he tries to address the middle of the field.

-Schwartz was very vocal today and was dropping the F-bombs like nobody's business. After practice, the veteran DC was stressing consistency and is getting a little tired of his players failing to learn from their mistakes. The lone exceptions he said were Jenkins and McLeod, who have been stellar to date.

"We'd make a play, give up a play. Make a play, give up a play," Schwartz complained. "That's not a way to play defense; that’s not a way to play football. We've got to be consistent and that's our challenge. Our challenge is ironing that out, not just individually with guys but as a unit, we have to be more consistent. And that goes for everybody.

"...when I say we haven't been consistent as a defense, I'd probably like to exempt those two guys (Jenkins and McLeod) because they've played very, very consistently. They're great communicators and we need more guys following suit."

-McLeod in fact, who also had a helmet cam today, is on a four-day interception streak and looks like a real difference maker on the back end as both a coverage guy and intimidator.

-Trey Burton continues to impress and his versatility is a real asset to the point that the Eagles are going to have to find ways to get him on the field. For the second straight day, the backup tight end lined up outside the numbers and was able to beat a cornerback, this time Ron Brooks, on a fade pattern. If that scenario happens on game day, you might be able to get Burton matched up with a safety or even a linebacker and that's advantage Eagles. Meanwhile, he also got the ball on a bubble screen out of a bunch formation.

-The Eagles waived/injured Connor Wujciak after the undrafted rookie defensive tackle underwent season-ending shoulder surgery. The Boston College product also broke his hand in offseason work and had fallen behind fellow UDFA's Destiny Vaeao and Aziz Shittu on the third-team defensive line.

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