While the feeling is that the Eagles offense has too much talent to struggle this season, the defense has not yet inspired that level of confidence due to poor tackling and an inability to get off of the field on third downs in the Eagles preseason opener against the Steelers.

Those two problems that plagued the Birds defense last year were still present in the first preseason game and with the schedule forcing the Eagles to play their third preseason game just four days after their second, Monday night is the best shot for the starters to show improvement.  The first string will play at least a half and maybe into the third quarter.

“The key is the third downs,” said defensive coordinator Juan Castillo. “We practiced pretty well and in the first game we had about five or six third downs and we were one out of six so that is something we need to improve this week. We did a good job in practice at Lehigh after the game but we need to improve that.”

“You know we want to get off the field," said defensive end Brandon Graham. "Why go hard for the first two downs and then the last down, where you need it to get off the field, why back off?

"That’s what we really made adjustments and stuff like that just on what we need to do and most of the time, it’s just blown assignments and that’s something we can control.”

When it came to missed tackles, Jaiquawn Jarrett, a second-year safety, was one of the biggest offenders.  Jarrett started for the injured Nate Allen, who is now back in the mix.  Still, when Jarrett’s number is called, he’ll be expected to improve.

“J.J. is a competitor and really the next practice that we had at Lehigh he came out there and showed the type of physical presence he can be,” said Castillo. “We expect him to come back and do a good job.”

Allen wants to see the secondary begin to form the type of chemistry that will improve communication and results on the field this year.  Allen and Kurt Coleman are the current starters at safety, while Nnamdi Asomugha and Dominique Rodgers-Cromartie top the depth chart at cornerback.

“You definitely have to be on the same page, especially going against Tom Brady and the Patriots,” Allen said. “They’re precise, and we have to be ready as a secondary. Everybody has to be on the same page.”

While the Eagles starters will see their most extended playing time of the preseason against the Patriots and will spend more time game planning than in other exhibitions, they still won’t show all of their cards.

The Patriots offense boasts a pair of lethal tight ends in Rob Gronkowski and Aaron Hernandez, and in the regular season Nnamdi Asomugha would probably be moved around in coverage.  That may not happen very often on Monday.

“There’s some things we could probably do in the New England game that if it was during the season we would not do,” Castillo said. “I think it depends on the receiver and with [cornerback] Dominique [Rodgers-Cromartie] the same thing. I think during the season there will be some things we do that we’re not going to do during the preseason just so that we still have an advantage with those two guys.”

Regardless, the test the Eagles defense needs to pass is not one of scheming or game planning, but one of simple execution.  If the Eagles can execute when tackling and avoid costly mistakes on third downs that extend drives, they should head toward the regular season with confidence.

If not, questions are likely to remain when they face the Browns in just over three weeks.

Ryan Messick covers the Eagles for 97.3 ESPN FM.  Follow him on Twitter.