Two years later, he has a chance to prove they gave up on him too soon.
"I'm trying to prepare myself, make sure I'm not too excited, too hyped," Kolb said Wednesday. "As a quarterback, you have to be settled in. I have a lot of respect for those players and coaches."
Kolb will lead the Arizona Cardinals against Philadelphia in a matchup of 2-0 teams on Sunday. He's doing his best to treat this like any other game, though it certainly has a personal flavor.
The Eagles selected Kolb in the second round with their first pick in the 2007 draft, even though McNabb was firmly entrenched as the starter. Coach Andy Reid and offensive coordinator Marty Mornhinweg groomed Kolb to be McNabb's successor. Kolb studied hard, prepared, took mental notes, and did whatever he could to be ready when he received the chance.
When McNabb was injured in the 2009 opener, Kolb stepped in and became the first player in league history to throw for 300 yards in his first two starts. Then he went back to the bench.
His time finally arrived in 2010 after the Eagles traded McNabb to Washington. Kolb had big cleats to fill, taking over for the most successful QB in franchise history. McNabb went to six Pro Bowls and led the Eagles to five NFC Championship Games and one Super Bowl loss in 11 seasons in Philadelphia.
But Kolb sustained a concussion in Week 1 against Green Bay, paving the way for Michael Vick to make a remarkable comeback. The rest is history.
"Everything happens for a reason," Kolb said. "That's how I go about life."
Kolb started three more games after Vick was injured, leading the Eagles to a pair of wins in October. He played well, but went back to the sideline when Vick returned.
Despite all the back-and-forth, Kolb has no resentment about his time in Philadelphia.
"It's definitely not bitterness," he said. "I learned so much there. I have a lot of fond memories there, actually. I think about it all the time. I think the one thing it taught me was not let the highs and the lows affect you that bad because you never know when the next opportunity will be and how quick it can change."
That was a valuable lesson for Kolb.
In July 2011, he was traded to Arizona for cornerback Dominique Rodgers-Cromartie and a second-round pick. Hoping they had their first franchise quarterback since Kurt Warner retired, the Cardinals signed Kolb to a five-year, $63.5 million contract extension with $21 million guaranteed.
Again, it didn't pan out as planned.
Injuries plagued Kolb last season and he ended up starting just nine games, going 3-6. Then he lost out to John Skelton in a preseason competition this year.
Skelton, however, injured his ankle in the opener against Seattle. Kolb stepped in and engineered the winning touchdown drive. He then led the Cardinals to a 20-18 win over New England, becoming the first quarterback to beat Tom Brady in an opener at Gillette Stadium.
"It's somewhat ironic, but I'm taking it day by day, game by game," Kolb said. "I learned I'm not going to try and predict anything. I went through a lot. I learned a lot from it. I learned don't sulk, don't feel bad for yourself. It can all happen in a hurry."
Kolb has plenty of friends in Philadelphia, including Vick. Tight end Brent Celek already exchanged text messages with Kolb and Vick plans to do so, as well.
"We all know Kevin is a competitor and I know him as a great friend," Vick said. "I know he'll be amped up this week, so we have to be ready for him. That Green Bay game (in 2010), I never thought I'd be playing that day. I never knew where my career was going to go."
Kolb didn't play because of a turf toe injury when the Cardinals beat the Eagles 21-17 in Philadelphia last November. Still, he may have made a difference by standing on the sideline and helping the defensive players identify some of Philadelphia's plays.
The familiarity goes both ways, though.
"We know a few of his tendencies, but he's in a new offense and he has a new confidence, so we have to prepare like any other quarterback and take what we know about him and keep it in the back of our mind," safety Nate Allen said. "We have to stick to what we do, disguise our coverages, try to confuse him any way we can."
The Eagles will certainly try to rattle Kolb by hitting him hard and often. Kolb received a scathing review from Raiders defensive end Tommy Kelly after he sacked him in a preseason game. Kelly called Kolb "scared" and "skittish."
Kolb said the accusation is "ridiculous" and no one plays scared in the NFL.
"We have to put the pressure on him," Eagles defensive end Brandon Graham said. "That's what we saw happen to him here. When you put the pressure on him, he's a different guy. But if you let him sit back there, he can pick you apart a little bit."
WR Jeremy Maclin (hip), T King Dunlap (hamstring) and S Colt Anderson (knee) didn't practice Wednesday. Reid said Maclin made "improvement." He said Dunlap would be a "stretch" to start vs. Arizona. Demetress Bell, who replaced him against the Ravens, would take his place. ... The Eagles lost to the Giants, 29-16, in Week 3 last season.