NEW ORLEANS - In what sounds like an obvious statement after the last two games, the Eagles' decision to fire Juan Castillo over the bye week was labeled a "miscalculation" by a senior Eagles staffer following a 28-13 loss to the Saints on Monday night.

In an attempt to shake up the team after a disastrous overtime loss to Detroit on Oct. 14, Eagles coach Andy Reid fired Castillo as defensive coordinator and replaced him with defensive backs coach Todd Bowles.

But the switch seems to have backfired on Reid.

Bowles' unit has become worse across the spectrum - in points, yards, in the red zone, and on third down. In the first six games under Castillo, the defense allowed an average of 16.8 points and 330.8 yards a game and was among the league leaders on third down (41.2 percent) and in the red zone (42.1).

Under Bowles, the defense has surrendered an average of 25 points and 381.5 yards a game, and has struggled on third down (50 percent) and in the red zone (66.7). The Eagles have also had a number of ill-timed penalties in the last two games and have tackled poorly, especially in New Orleans.

"Our tackling was not anywhere near what we are capable of doing," Reid said Tuesday at the NovaCare Complex. "We have a couple of key penalties there that enhanced field position for New Orleans."

Bowles had never been a coordinator in the NFL. He was hired in January after a stint with the Miami Dolphins that ended with him as interim head coach for three games in 2011.

Castillo was promoted from offensive line coach in January 2011, a move that was criticized by many at the time. Castillo struggled in his first year as coordinator, but his defense showed improvement in 2012.

But back-to-back fourth quarter collapses against Pittsburgh and Detroit led to his firing.

Bowles hasn't had the opportunity to blow any fourth quarter leads because his defense has put the Eagles behind in the last two games. The Falcons scored on their first six possessions in their 30-17 win over the Eagles on Oct. 28.

The defense showed marginal improvement against the Saints, but could not keep the Eagles in the game after Michael Vick threw a pick-six that spotted their opponents a 7-0 lead.