The possibility had some appeal when Jackson struggled during a 23-17 home defeat to the Washington Redskins last week. But with Jackson playing efficiently and making big plays down the field during a 31-14 victory against Philadelphia on Thursday night, the team cannot reasonably remove him from the lineup.
Jackson's struggles against Washington appeared related to his pectoral injury. He struggled to make throws he seemed to be making previously. In retrospect, Jackson's ability to practice extensively early in the week and play well only four days after the Washington game suggests the injury wasn't such a limiting factor, after all.
Having the earliest game in Week 13 and the latest one in Week 14 gives Jackson an extended period to rest his injury. There still could come a time when giving Portis a look makes sense. The coaching staff likes him enough to justify such a move if Jackson's health deteriorates or the medical staff thinks keeping Jackson in the lineup risks an injury threatening his 2012 season. It's less practical making such a move with five games remaining if Jackson can still play the way he did against the Eagles.
Jackson completed 13 of 16 passes for 190 yards and one touchdown. He posted the second-highest passer rating (137.0) of his career as a starter. His Total QBR score (76.9) beat the previous season high he set against Atlanta in Week 4 (68.2).
Jackson completed 6 of 8 passes for 89 yards on third down. His Total QBR for third-down plays stood at 93.5 out of 100, according to ESPN Stats & Information. Overall, he completed 5 of 6 passes for 111 yards throws traveling more than 10 yards past the line of scrimmage.
The Eagles continued their season-long trend of sending four or fewer pass-rushers the vast majority of the time. Jackson, playing without top receiver Sidney Rice, picked apart a secondary that lost top corner Nnamdi Asomugha to injury. The Eagles' third corner, Dominique Rodgers-Cromartie, missed the game entirely. The Eagles also lost safety Colt Anderson to a season-ending knee injury during the game.
The chart ranks Jackson's performances this season by Total QBR, which takes into account how quarterbacks affect win probability through passes, runs, sacks and penalties. I've included NFL passer ratings for a look at raw passing as well.