PHILADELPHIA (973espn.com) - The Eagles started their second week of voluntary on-field OTAs Tuesday and we've already seen some significant shake-ups on Jim Schwartz's defense.

The veteran defensive coordinator, who is moving Philadelphia's defense back to a 4-3 attacking scheme, gave rookie seventh-round cornerback Jalen Mills, recently-signed defensive tackle Mike Martin, and corner-turned safety Jaylen Watkins significant looks with the first-team defense, a sharp contrast from last week.

Schwartz, however, said not to read too much into his shuffling.

"If you come back tomorrow, you'll see something different," Schwartz said after practice. "Right now it's so early guys are really just competing against themselves to improve technique. We don't have a depth chart right now."

Fair enough Jim but there are certainly guys who are entrenched with the ones and not taking reps with others so there has to be a little something that spawned an interest in seeing certain players against the top group on offense.

In the case of Mills, he saw a lot of time on the outside opposite Leodis McKelvin with Ron Brooks in the slot. The odd man out being second-year man Eric Rowe, who heard it from defensive backs coach Cory Undlin in at least one occasion for some technique issues in coverage.

As for Martin, he was the placeholder for the absent Fletcher Cox on Tuesday, stepping past Taylor Hart, who certainly seemed ill-suited for the three-technique spot. Obviously when Cox returns he steps in as the starter but the Pro Bowl star needs a backup and Martin, a former third-round pick out of Michigan, at least has the skill set to play the position.

Watkins was the strangest move because he was taking the place of star safety Malcolm Jenkins and that truly was Schwartz just trying to take a look at an option against different players because he made sure to say that is prospective back end of Jenkins and free-agent pickup Rodney McLeod is already shaping up as one of the best duos in all of football.

"I'm going against my own rule here of judging players early but I don't see why they (Jenkins and McLeod) can't be one of the better tandems in the league," Schwartz said.

BIRD DROPPINGS:

-Wide receiver Rueben Randle missed practice today after undergoing gallbladder surgery while starting running back Ryan Mathews was also out with an undisclosed illness. Cox and Darren Sproles, meanwhile, continue to stay away from the voluntary portion of OTAs. Without Mathews and Sproles available, Kenjon Barner was the No. 1 running back with rookie Wendell Smallwood seeing plenty of action.

-Cornerbacks Nolan Carroll and JaCorey Shepherd continue to be held out of the team drills as they work their way back from injuries but kicker Cody Parkey was back in a limited fashion, although he's not expected to be 100 percent until training camp.

-Rowe spent most of his time on the second team with Denzel Rice, who had a rough go of it and was tongue-lashed by both Schwartz and Undlin for not touching Jonathan Krause on the ground after the receiver beat him.

-Brandon Graham continued to run behind Connor Barwin at right defensive end but did get some first-team reps on the left side in place of Vinny Curry so it's pretty clear those three will fit into the rotation on the edges.

-Seventh-round linebacker Joe Walker, who also had a rough day according to Schwartz, nearly picked off Chase Daniel during 7-on-7 drills.

-WRs coach Greg Lewis continues to be the most vocal of Doug Pederson's staff and Pederson himself is much more hands on tan Chip Kelly.

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