CHICAGO (AP) - The way Nick Foles struggled and Mark Sanchez moved the team, it was hard to tell which quarterback was the star and which one was the castoff.
Foles threw two interceptions, to match last season's total, before Sanchez delivered a sharp performance in relief in the Philadelphia Eagles' 34-28 loss to the Chicago Bears in the preseason opener for both teams on Friday night.
''We can't have the errors that we had to start the game on offense, whether it be the interceptions or the penalties,'' Foles said. ''What preseason allows is an opportunity to clean it up. That's what we'll do as a team. We'll clean it up and we'll move forward.''
For Foles, it was simply a brutal night. The quarterback who posted the NFL's highest passer rating and threw just two interceptions in 13 games last season couldn't get in sync even though Chicago's Jared Allen sat out.
The five-time Pro Bowl defensive end and prized offseason acquisition missed practices this week because his wife gave birth to a girl.
Even with Allen out, Foles got rattled early. He wound up with 44 yards on 6-of-9 passing before Sanchez, a castoff by the Jets, took over.
Sanchez was 7 for 10 for 79 yards against backups on defense.
''I thought Mark did a really nice job,'' Eagles coach Chip Kelly said. ''I was really impressed with the work he did in the second quarter. I thought he played calm. He had poise about him. He put the ball on the money.''
Meanwhile, Chicago's Jay Cutler looked sharp in his brief stint, and the two quarterbacks vying for the backup spot had their moments, too.
Cutler completed 9 of 13 passes for 85 yards.
Palmer relieved him and went 8 of 11 for 104 yards, shaking off an interception to throw a touchdown pass.
Clausen started the third quarter and threw for 150 yards and two touchdowns, including a 73-yarder to Williams along the right sideline. Later in the quarter, he connected with Michael Spurlock on a 22-yard scoring pass and hit Dante Rosario on the two-point conversion to put Chicago ahead 31-28.
''I like the way (Palmer) brought the team back,'' coach Marc Trestman said. ''He came back and moved the football team. And the same thing with Jimmy. I thought he moved the football team, was poised for a guy who's been here so little time.
''I think we saw something there, as well, so that competition continues.''
Zach Miller caught six passes for 68 yards, including touchdowns from Cutler and Palmer.
Philadelphia's Matthew Tucker ran for 40 yards and two touchdowns before leaving with a hamstring injury. Josh Huff returned a kickoff 102 yards late in the first half to give the Eagles a 21-14 lead.
Foles' troubles started on the game's first possession when he got pressured and threw the ball right to Ryan Mundy, resulting in an easy interception for a player vying for time at safety.
Cutler led the Bears on a 69-yard touchdown drive on their second possession, finishing it with a 10-yard strike to Miller to make it 7-0.
Foles then had the Eagles threatening, but with the ball on the 32, a short pass intended for Zach Ertz got picked off by Sherrick McManis.
Sanchez was decisive, on target and a big reason why they scored touchdowns on three straight possessions to take a 21-14 halftime lead.
He led them on 53 and 51-yard scoring drives that ended with short runs by Tucker to put Philadelphia up 14-7.
Palmer answered with a 12-yard TD to Miller to tie it for Chicago with just over a minute left, but in a flash, the Eagles regained the lead. Huff returned the kickoff 102 yards untouched up the left sideline to put them up 21-14 at the half.
''The one thing he can do is he can finish,'' Kelly said. ''He's a big, strong guy.''
Notes: Philadelphia's Jeremy Maclin had one 15-yard catch after missing last season with a torn ACL. ... Asked if Bennett will practice on Sunday, Trestman said, ''It has not been decided.'' ... Trestman said safeties Chris Conte (shoulder) and Craig Steltz (groin) are ''very close'' to being cleared to practice - possibly next week. Both are on the physically unable to perform list.
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