The Eagles’ offense ought to look better Sunday against Detroit than it looked in the early going in Atlanta, Mike Groh said, even though the team probably will still be missing DeSean Jackson, Alshon Jeffery, and Dallas Goedert.

The biggest difference will be having all week to practice and prepare with the offensive pieces that are left, Groh said Tuesday, instead of trying to fit them into a game plan designed mostly for guys who were out of the Atlanta game by the end of the first quarter.

Groh and rookie wideout J.J. Arcega-Whiteside described a hectic Sunday evening on the Eagles’ sideline, as everyone, including quarterback Carson Wentz, tried to adjust to a situation they couldn’t have anticipated.

“It’s never happened to me, in all my time coaching, to lose three skill position guys like that so early in a game,” said Groh, the team’s offensive coordinator. He said he was proud of his players and position coaches, who figured things out well enough that “we were able to settle in and finally find a rhythm.”

Goedert felt pain from a preseason calf injury in pregame warmups and the tight end never took the field, which meant Zach Ertz had to play all 81 snaps. Jeffery played just six snaps before leaving with a calf problem. Jackson, the other starting wideout, was in and out and finally out for good after 11 snaps with what was described as a groin injury. ESPN called it an “abdominal strain” Tuesday and said Jackson would miss about two weeks, which is more or less what was expected.

The Eagles play at Green Bay four days after they face Detroit, so it seems unlikely anyone who misses this week’s game is going to heal quickly enough to play there. Then there is a break until an Oct. 6 home game against the Jets.

Arcega-Whiteside played five offensive snaps in the season opener. He had lots of family and friends Sunday at Mercedes-Benz Stadium, playing a few hours down I-85 from his hometown of Roebuck, S.C. Arcega-Whiteside and Mack Hollins, who are bigger receivers, had spent much of the practice week mimicking Atlanta’s Julio Jones.

“It was crazy because I was just kind of there, ready … At a moment’s notice, they said, ‘All right, you’re going to play the rest of the game.’ I got excited. ‘I’m like, all right, cool, yeah, let’s go do this,’ ” Arcega-Whiteside said. He played 75 snaps, catching his first NFL pass, for 4 yards. He was targeted four times.

“It was unexpected, but that’s why we prepare as hard as we do,” Arcega-Whiteside said.

Nelson Agholor, Hollins, and Arcega-Whiteside are going to need to be better this week against Detroit. Agholor played both outside and in the slot, catching eight passes for 107 yards and a touchdown, but he literally had the game in his hands and dropped it when he couldn’t handle a perfectly thrown Wentz bomb on the final series. Hollins caught five passes for 50 yards, on eight targets, sometimes failing to get separation.

“Everything could have been better,” Arcega-Whiteside said, when asked how he felt it went. “You can’t simulate game reps. Having [75] game reps, just like that, helps out a lot for me. The game started getting slower and slower and I started picking up things faster and faster.”

He said his mistakes were “little things here and there.”

Groh, asked about Arcega-Whiteside’s evening, said: “He’s got plays he did very well on, and plays that we come back and look at and try to make our corrections, go on from there.”

Groh said “the game didn’t look too big” for Arcega-Whiteside or Hollins, but things happened that they would learn from.

Groh said the biggest problem with adjusting the game plan was “massaging the personnel groups. There’s a lot of plays on there specific to personnel groupings. Some of those, we feel like we could interchange a guy. Others, you gotta cross off the list.

“Maybe plug a guy in and rep a play [after telling a player], ‘That was a different personnel group, I know you didn’t get this rep. Here’s how you want to execute the route assignment or the blocking assignment,’ whatever the case may be.

“There’s a lot of communication that has to go on in a short amount of time to get that done. We got mentally flexible guys who can handle that … and the coaches did a great job of making those adjustments.”

At one point, Agholor was off the field, being checked for a concussion, leaving Groh with just Arcega-Whiteside and Hollins at wide receiver. Had Agholor not passed the concussion test, 36-year-old running back Darren Sproles was going to expand his horizons with a stint at wide receiver, Groh said.

“Alshon was there to greet me every time I was on the sideline,” Arcega-Whiteside said. “Sometimes, when I was lined up on the side that we were on, he was there watching, and would say ‘Hey, watch this and watch that.’ ”

Groh said having time to plan this week entails considering such things as “maybe play a little bit of a different kind of a game. There’s an element of surprise to that, too.”

Arcega-Whiteside said he feels he has a generally good rapport with Wentz, but certainly could use some first-team practice reps,

“Obviously, this week it’s going to ramp up a little bit more. We’re going to get that chemistry going a lot better than what we’ve had,” he said.

If the Eagles need a bigger contribution from him, in his third NFL game Sunday, and then again in his fourth, at Green Bay, “I’m ready,” Arcega-Whiteside said. “That’s what I’ve dreamed about, that’s why I’m here, to help this team win.”