The Eagles and Redskins were tied at 27 in the fourth quarter last Sunday when Foles went down hard after a blind-side block by Washington's Chris Baker on an interception that ended up being overturned by replay.
All-Pro tackle Jason Peters immediately jumped to Foles' defense, went after Baker and both players were ejected.
Once the melee cleared and both teams returned to their sidelines, Foles was back in the huddle for the next play. He made some of his best throws on the drive and capped it off with a 27-yard touchdown pass to Jeremy Maclin.
The Eagles (3-0) didn't relinquish the lead and held on for a 37-34 victory.
While many praised Foles for demonstrating toughness on the play, he simply reinforced Kelly's opinion.
"I think you've got to respect Nick," Kelly said Wednesday. "I've said it all along. I saw him do it in college. We hit the heck out of him when we were at Oregon and he played at Arizona and he just kept getting up and throwing and standing in there.
"I think it's a very underrated quality for a quarterback. It's not something you can see at a pro day. It's not something you can see at the combine. They're never getting hit. They're doing everything in shorts and T-shirts. But you've really got to study the tape."
The 6-foot-6, 243-pound Foles has missed one start because of injury in his three-year career. He suffered a concussion on a hit against Dallas last Oct. 20, sat out the following week and returned to throw an NFL-record tying seven TD passes at Oakland on Nov. 3.
Baker's block wasn't the only shot Foles took from the Redskins. He withstood several hits in the pocket, completed passes under pressure and didn't take any sacks.
"No matter who you are playing that position, you're going to get hit," Kelly said. "You've got some big, angry people running after you and trying to take you down.
"To stand in there and not worry about it and know you're going to get hit, but you have to deliver the ball on time is a really underrated quality at that position. Right now he's really showing what I've seen all along from him. Our players here understood it. It didn't take Sunday's game for them to admire his toughness."
Still, teammates raved about Foles.
"When you have a quarterback that will do whatever it takes, stay in the game, play his heart out, even if you know he's feeling so bad, you can't respect a guy enough," center David Molk said. "That is amazing."
The mild-mannered, soft-spoken Foles was uncharacteristically fired-up after the hit, telling players in the huddle he wanted to make the Redskins pay for what the team considered a cheap shot.
"The leadership that Nick provided after that was great," tight end Zach Ertz said.
Foles thrived last year playing behind one of the league's best offensive lines. Peters, All-Pro guard Evan Mathis, center Jason Kelce, right guard Todd Herremans and right tackle Lane Johnson started 17 games together, including playoffs.
When the Eagles visit the San Francisco 49ers (1-2) on Sunday, only one guy — Peters — will start at the same position as last week.
"Football is a contact sport where you are going to get hit," Foles said. "I know part of playing quarterback is standing in that pocket and getting hit no matter what. You always try to get the ball out in a timely manner. You can't hold it too long. Sometimes it takes longer because of what we have called, but you trust those guys to block for me."
NOTES: Told the NFL said Baker won't be fined for the hit on Foles, Kelly said: "That's news to me that that's a legal hit." ... LB Mychal Kendricks (calf) didn't practice Wednesday. DE Fletcher Cox (back) was a limited participant.
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