ENTERING the 2013 season, two reigning contentions concerning the Eagles' new offense were:
* Michael Vick had to stay healthy and effectively run Chip Kelly's high-octane offense. Vick had to learn it, execute it and avoid major injury.
* Fifth-year receiver Jeremy Maclin had to be Vick's most consistent weapon. Speedy receiver DeSean Jackson was going to get help from safeties; defenses would key on running back LeSean McCoy; tight end Brent Celek would have to help rookie right tackle Lane Johnson keep Vick's blindside clean.
Neither Vick nor Maclin had proven understudies. So, among the dozens of unknowns facing a rebuilt Eagles roster and coaching staff, both Vick and Maclin occupied positions of consternation.
Vick shredded his hamstring in Game 6.
Maclin blew out his knee in training camp.
The Eagles' offense ranks third in yards and eighth in points.
Nick Foles is the highest rated passer in the NFL by 10 points.
Riley Cooper, Maclin's replacement, has caught 34 passes for 640 yards and seven touchdowns, which, if continued, would compare favorably with any of Maclin's four seasons.
Once, Vick and Maclin seemed integral to the success of Kelly's machine-gun scheme.
Now, both players might be superfluous to the Eagles' future. Both are free agents after the season; both have plenty of football left in them. But, if both want to be guaranteed a starting spot, they likely will be doing so elsewhere.
They float around the NovaCare Complex, seldom seen, almost never heard. Maclin rehabs in the mornings. Vick is back as the backup after 6 weeks of limited availability, or non-availability, but he seldom surfaces anywhere but the practice field.
Still, this question is intriguing: As potent as the offense has been, where might the Eagles be with Vick and Maclin?
Maybe inside the playoff picture, looking in, instead of just outside.
Maybe 8-4 or 9-3 instead of 7-5.
Maybe 4-1 in the division instead of 3-2; their home loss to the Giants was abysmal.
Vick, behind a sporadic offensive line, carried the offense in the first two games.
Foles, behind a much better assemblage, has pushed the attack ahead.
There is logic behind the successes enjoyed behind these lines in question.
The Eagles entered 2010 with an established front, which injury eroded as the season wore on.
The Eagles switched line coaches for the 2011 season, a philosophical shift in technique for a group of established veterans that required adjustment.
The Eagles never had a chance in 2012, wracked by injury. Left tackle Jason Peters, the team's best player, never played. Center Jason Kelce was lost in Game 2. Right tackle Todd Herremans missed the second half of the year.
None of their three replacements has played a snap for the Eagles this season. Two of them - Demetress Bell and King Dunlap - are not even on the 2013 team.
The Eagles in June drafted Lane Johnson to play right tackle, moving Herremans to right guard, where he had never played.
All of this meant Vick seldom was afforded the time to make decision that Foles has had.
Vick ran 33 times for 307 yards in his five starts to begin the season, usually as a result of pressures from his right or up the middle - or, the side of the line manned by Kelce, Herremans and Johnson.
Vick averaged 9.3 yards per carry, his best average as a starter, but his well-worn, 33-year-old body could not handle the load; in the sixth game he pulled his hamstring.
He returned for the rematch against the Giants 3 weeks later but aggravated the injury. The Eagles' offense did not score. Foles and fourth-round rookie Matt Barkley seemed grossly overmatched; Cooper, an insignificance in cleats.
Then, the line righted itself.
Suddenly, Foles was given time to plant and heave. Cooper, a 6-3, 222-pounder with major league outfielder skills, was given time for his routes to develop and to be pegged as a sure-handed target deep in a progression.
"He's impressed me," said offensive coordinator Pat Shurmur. "I like big guys. And he finds a way . . . When it gets thick out there, as the game goes on, everybody kind of gets tired. Riley doesn't get smaller, you know. And I think big guys find a way to make plays when there are people around them."
Maclin, at 6-feet and 198 pounds, is not exactly small, but, really, he was drafted in the first round for his speed more than his size. He has been worth that pick, and more.
Maclin's 258 receptions are the most by any Eagles receiver in their first four seasons, his 26 touchdown catches the sixth most; both are more than his more famous teammate, DeSean Jackson. Of course, Jackson leads among receiving yardage in his first four seasons among Eagles, but Maclin is third.
Vick, too, made his mark in Eagles record books. He led the team to franchise records, with 439 points in 2010 and 6,386 yards in 2011.
Neither of those records is in danger of being broken this season.
Of course, both Vick and Maclin played in 2010 and 2011.