"It sucked, man, it really did," Cooper said. "It was really frustrating for me because I felt so good headed into camp."
Cooper is all the way back now, having made his 2012 debut against Detroit and following it up against Atlanta on Sunday in roles similar to those of last year.
Against the Lions, Cooper played only 10 snaps on offense, but was targeted on three of them. He ended the game with two catches for 18 yards, and had an additional grab nullified by penalty. More important, Cooper picked up where he left off in 2011 with a strong performance on special teams, a unit that had been dismal without him.
"It was great. Everything felt good. I graded out good," Cooper said last week. "I was playing physical on special teams. Once you get that first hit out of the way, then mentally you're like, 'OK, it's good,' and you're ready to go, you're ready to rock. I had to get that first lick in and I felt great."
Cooper's snap count on Sunday grew to 19, no doubt aided by the need for points born out of an early deficit. But he was only targeted once in Michael Vick's 35 pass attempts, and was held without a catch as the Eagles' offense continued to stall.
At this point on offense, Cooper is just a fourth receiver. But standing 6-3 and weighing more than 220 pounds, he is easily the Eagles' biggest wideout, prompting hope that he could be a factor in a red-zone offense that has foundered for what seems like years now. The Eagles have converted their red-zone trips into touchdowns at a meager rate of just over 45 percent, 25th in the league.
All around the pass-happy NFL, third and fourth wide receivers are making an impact. Look no further than within the Eagles' division, where no-names like the Redskins' Leonard Hankerson, the Giants' Ramses Barden and the Cowboys' Kevin Ogletree have had their moments this season.
The Eagles' offense under Andy Reid used to take pride in spreading the ball around, but until that starts to happen again, Cooper said all he can do is concentrate on his current role.
"We have so many great receivers on this squad," Cooper said. "Our top three guys are some of the best in the league.
"Everyone's time comes, as I say, and I am just waiting for my time and learning from these guys and being the fourth wideout. Making catches when I can - in those four-wideout sets."
Cooper showed flashes of emergence last year when he filled in admirably for an injured Jeremy Maclin. Over three games as a starter, Cooper had 13 catches for 240 yards and a touchdown. But after July's injury, that performance seems like a distant memory.
"It is too far out - projecting how good I am going to be or anything like that," he said. "I just have to deal with what is happening right now."
With the offense clearly struggling, it will be interesting to see how Cooper's role develops in the remaining nine games.
Cooper claims to have felt great for more than a month now, and says he has no restrictions on the field. While he is still hoping to see more time at receiver, his chief concern is helping to improve a special-teams unit that is crucial, considering the inconsistency on offense and defense.
"Special teams is a big factor for me," Cooper said. "We are going to improve. We have to improve.
"In every aspect of the game, you have to try to improve - offense, defense, special teams - to win games. Just keep getting better. Not saying we weren't, but we have to play real physical."