Photos: Saints turn in mistake-filled performance against Eagles in 39-17 loss; drop to 1-4 _lowres

Associated Press photo by Matt Rourke -- Saints cornerback Damian Swann breaks up a pass intended for Eagles tight end Zach Ertz in the first half Sunday in Philadelphia. Swann later left the game with a head injury.

The first start of Andrus Peat’s Saints career ended up a little bumpy.

Peat gave up two sacks, including a strip-sack by Fletcher Cox that proved to be the momentum-turning play in a 39-17 loss for New Orleans at the hands of Philadelphia.

The big rookie from Stanford also had several good moments, but the No. 13 pick said he wished he had played a little better.

“I felt like there were some ups and downs. Obviously, I wish I could have done better, done a better job in protection,” Peat said. “I feel like all I can do is improve for the next week, and that’s what I’m going to focus on going forward.”

Peat faced a daunting task. Forced into action by a knee injury to left tackle Terron Armstead, Peat had to fill in for a third-year tackle who has made a case to be included among the NFL’s top tackles through the first four games of this season.

For the most part, Peat acquitted himself well. The first sack he gave up may not have been his fault; Drew Brees held the ball for more than three seconds and gave the defender a little extra time.

But Peat would like to have the second back. New Orleans called a play-action pass that required the offensive line to block down to the right, and Peat drove a little too far on Cox.

The veteran Eagles lineman used Peat’s momentum against him, broke free and strip-sacked Brees to give Philadelphia the ball on the New Orleans 13.

“It was a play to the right, and my guy kind of stayed back behind me,” Peat said. “I’ve just got to do a better job.”

No substitute

The Saints can’t get punter Thomas Morstead back soon enough.

New Orleans signed veteran Brandon Fields, who entered the game tied with Morstead for the second-best gross average all-time at 46.8 yards, to be a capable fill-in after Morstead suffered a strained quadriceps against Dallas.

Fields started strong, hitting a knuckler that rolled all the way to the 19-yard line for a 57-yard offering in the second quarter, then pinning the Eagles at their own 7-yard line with a 37-yard lob wedge two series later.

But the former Dolphin couldn’t keep it going.

With the Saints trailing 23-10 and desperately needing something to help get a little momentum midway through the third quarter, Fields shanked a punt that went out of bounds after just 13 yards, offering Philadelphia a short field that Eagles turned into a field goal.

Fields also badly mis-hit a fourth-quarter offering from near midfield that traveled only 36 yards.

“We struggled punting the ball,” Saints coach Sean Payton said. “That was obvious.”

Earlier in the week, Payton said the Saints expect Morstead back soon. With a game against the Falcons looming Thursday, New Orleans needs him back as soon as possible.

Beat up, banged up

Damian Swann, the rookie cornerback for the Saints who earned a key role, went out with a head injury.

Swann, who has been an integral part of the defense as a nickel and dime cornerback, left the game in the first half. At that point, he’d made a key breakup on Eagles tight end Zach Ertz, who ended up making five catches for 60 yards.

With Swann out of the game, the Saints turned to veteran Kyle Wilson, but Wilson also suffered an injury early in the second half, returned to the game briefly and then left again with a leg injury late in the fourth quarter.

Wide receiver Marques Colston, who made three catches for 36 yards, left the game late in the second half with an arm injury, according to Fox sideline reporter Tony Siragusa.

Left guard Tim Lelito, who missed a practice on Thursday with a back injury, also left the game in the fourth quarter, adding to a rash of injuries on the offensive line. In addition to Armstead, starting right guard Jahri Evans missed his third straight game with a knee injury despite practicing all week.

Rookie defensive end Bobby Richardson, who had risen to starter, was forced to miss the game because of a hip injury that sidelined him Friday.