Sheppard missed 5 games in 2007. Four of those games came early in the season, and one at the very end of the season.
Missed 3 games early in 2006.
missed 6 games at the end of 2005 (IR, as you mentioned)
Missed the final game of the 2004 season.
Missed one game late in 2003.
So, the past five years Sheppard has missed 16 games due to one injury or another, and he was banged up in others. Also, he's getting overrated by the fans on this board. He's a good CB, but not "one of the very best in the league", and he fits better in Philly's system.
Grade: 75 | Key
Comment: Sheppard is a six-year veteran out of Florida that was a first round pick of the Eagles in the 2002 draft. He has adequate size for the position but plays bigger than he measures. He has very quick feet and is close to being instant when he accelerates. He can pedal to extend the cushion but is a little tight in the hips when he has to turn and run with a receiver deep. If he gets behind by a step he can struggle to recover as he does not have premier top end speed. While he can be aggressive on run support he will pick his spots and can become a spectator at times. He is inconsistent in man-off or zone coverage and does not always get a great jump on the ball. He does not appear to have great route recognition or else he is trying to bait the quarterback into throwing to his man. He is best in press coverage where he can get his hands on the receiver and try to re-route him. Sheppard has good ball skills and can compete for the ball against even the taller receivers. He has struggled to get in a full season, missing one, then five and finally three games over the past three seasons.
79-70: Good Starter
Solid starter who is close to being an outstanding player ... Has few weaknesses and will usually win his individual matchup but does not dominate in every game, especially when matched up against the top players in the league.
Fernando Bryant (currently on the Patriots roster) grades out at 70.
Also, his complaints about his current contract, and wanting to be traded (so he can get paid) are the most notable reasons for the Eagles even wanting to trade him.
Switching 7th for 19th overall, and an injury-prone CB, who wants more money, doesn't seem like a great idea.
I wouldn't even give him that large contract as a free agent, so I obviously don't think he's worth that large contract, and first day draft picks.
Plus, the 2008 draft class is loaded with quality CB's, who'll be a lot cheaper.