McNabb, who quarterbacked the Eagles from 1999 to 2009, stood up for Reid while speaking to NFL Network's Judy Battista:
"The tough part about it—people in Philadelphia love what we did. As soon as things started to go south, everybody pointed the finger at Andy. It was wrong. Andy took it. Andy stuck his chest out and took it. I don't think it bothers him. But it pisses me off.
"It pisses me off because that's what they go to. You should not be defined by the championships you won but by the legacy you left. We wish we could have that one back in Super Bowl XXXIX, but how many coaches have the opportunity to get back 15 years later?"
Reid is the winningest coach without a Super Bowl title or NFL Championship in league history, per NFL Research. Battista noted that only Dick Vermeil waited longer between Super Bowl appearances, at 19 seasons.
Reid brought in McNabb to speak to the Chiefs prior to the team's practice Thursday.
Hall of Fame defensive back Brian Dawkins, who played under Reid in Philly from 1999 to 2008, chimed in on Super Bowl XXXIX on CBS Sports HQ on Wednesday morning (h/t CBS Sports' Jeff Kerr):
"The first memory I'll always remember is we lost. That's the first and final memory about that. Leading up to that, to go to at the time four NFC Championship Games, and the fourth being the one that we actually beat Atlanta to get there [the Super Bowl].
"So I remember the jubilation we had, to finally have the opportunity to play for that game. I can only imagine the 15 years to get back to this game again. Has a phenomenal team, especially on the offensive side of the ball."
Dawkins also lauded Reid:
"He's adapted and moved along with the game. He didn't stay in his mindset like he was with us. When he was with us, his mindset was we're going to win with these people. I say we can spread the ball out with these solid receivers and win games ... and we did win some games. But now, he has so much speed on the field they're doing so many things to exploit coverages, and there's certain things you can't do against this offense because of that speed.
"I just think he was able to evolve over the years, instead of stick with a specific game plan that he had earlier in his career."
Having 2018 MVP Patrick Mahomes obviously makes things easier, and the 24-year-old seems just as loyal to Reid as McNabb.
"We know we're playing a great opponent, but we're gonna try to win the game and get one for Coach Reid," Mahomes told NFL Network's Michael Irvin.
Reid was hired ahead of the 2013 campaign, and the franchise has finished above .500 each season since. Kansas City has won four straight AFC West titles and appeared in the playoffs for five straight years. Sunday night will present the opportunity to capture what Reid has never had and the Chiefs haven't claimed since beating the Minnesota Vikings in Super Bowl IV.
Super Bowl LIV between the Chiefs and San Francisco 49ers will kick off at 6:30 p.m. ET from Miami's Hard Rock Stadium.