The third-year receiver certainly has been targeted as infrequently in previous seasons, and one game is hardly an adequate sample. But Maclin's progress bears watching after he missed training camp and all four preseason games.
As long as he has any symptoms of the virus that sidelined him for weeks, Maclin and the Eagles said, he likely will need a few outings to get his football legs back.
"I felt fine," Maclin said after the game. "My legs are fresh. It wasn't any of that."
Four weeks ago, there was concern about whether Maclin could even play this season. The fact that he was even starting Sunday tempered expectations. But if the Eagles are going to reach 2010 heights - when they set a franchise record in points - Maclin has to be near 100 percent.
He is, it can be argued, the most important ball-catcher on the offense. Yes, DeSean Jackson stretches the defense and can score from almost anywhere on the field. But it's Maclin's precise intermediate routes that force safeties to play up and make the home run to Jackson possible.
He led all receivers in catches (70), catches for first down (45), and touchdowns (10) last season. He also was targeted more than any other receiver a year ago, 116 times. Against the Rams, though, Jackson (12) and Jason Avant (7) saw the ball thrown their way most often.
Jackson finished with six catches for 102 yards and a touchdown, but he dropped two passes, according to the Eagles coaches. Vick, though, accounted for a number of the other times they couldn't hook up.
The quarterback, overall, completed just 14 of 31 passes. (Officially, he had 32 throws, but one was a spike just before the half.) Vick's completion percentage was 44. Last year it was 62.6. His pre-2010 number was 53.7.
"In a normal game situation against a defense like that, I'm less concerned about completion percentage and more concerned about other things," Mornhinweg said. "However, I don't expect it to be that low."
The most obvious reason for the neglect of Maclin on Sunday was that Vick often took matters into his own legs when the Rams blitzed - which they did often. Last season, Maclin was Vick's go-to receiver when an extra rusher came his way. He caught 27 passes for 404 yards and five touchdowns against the blitz, according to Stats Inc.
"We didn't take advantage of some real easy things, and good football teams get the easy ones every time," Mornhinweg said.
Eagles coach Andy Reid wasn't pinning the blame solely on Vick for either not reading the blitz or taking off instead of throwing to the hot receiver.
"The receivers need to be dynamic on those plays where things are happening fast, and they've got to make sure they clear fast and that Michael gets the ball out fast," he said.
One encouraging sign - encouraging especially if Maclin needs another week or two to mesh with his quarterback - was that Vick had success going to other receivers in the red zone. Last season, Maclin led the Eagles with seven red-zone scores. No other receiver had more than two receiving touchdowns.
Against the Rams, though, Vick connected with running back LeSean McCoy for a 7-yarder and Jackson for a 6-yarder, and he probably would have had a third had Jackson caught what should have been a 16-yard touchdown before the half.
The Eagles can't go all season, however, with Maclin as the third or fourth option.
"He's too good a player," Mornhinweg said, "to have one catch."
Contact staff writer Jeff McLane at 215-854-4745, firstname.lastname@example.org or @Jeff_McLane on Twitter.