Packers wide receiver Greg Jennings celebrates a touchdown reception against the Saints on Sunday. (AP)

Packers WR Greg Jennings tried to play through a lingering groin injury against the Saints on Sunday and he even scored a touchdown. But it cost him.

Coach Mike McCarthy said Jennings reinjured his groin in Green Bay’s 28-27 win over New Orleans. McCarthy said it was a “flare up” of the same injury Jennings has battled since suffering a groin pull on the final series of the season opener against San Francisco.

“He could not open up all the way into a full stride, [that] was the concern,” McCarthy said Monday. “So, I would think we are back to where we were a couple weeks ago. We’ll see how he is Wednesday. He’ll go through the rehab process and then we’ll learn more.”

After taking himself out against the 49ers, Jennings missed the next week of practice and the game against Chicago. After that, he returned to practice but quickly suffered a setback. He was questionable going into the Week 3 game at Seattle, but played anyway. He was limited and came out after an incompletion in the first quarter. He later returned, but was nowhere near his elusive self.

Jennings didn’t practice much last week in advance of the Saints game, but started and caught a second-quarter touchdown that put the Packers up 14-7. That nine-yard score was his only reception.

The groin has been a pesky problem for Jennings, who hasn’t let the injury fully heal. McCarthy said it was “definitely an option” that the team could sit the veteran receiver out for a week or two.

In an unrelated Jennings injury story, S M.D. Jennings’ hurt shoulder isn’t overly serious, McCarthy said.

“Talking with the medical staff last night and again today, there’s not a high level of concern,” McCarthy said. “But you know how it is -- we’ll see how it feels [Tuesday]. We’ll test it before we put him on the field.”

Communication issue: Early in the game against the Saints, the Packers defense had some communication problems with the sideline that resulted in confusion on the field.

In a strategic move, Green Bay went with its “dollar” package, which uses seven defensive backs in the dime defense. The extra DB meant the Packers had to take out ILB D.J. Smith, who typically wears the radio headset and makes the calls in the dime defense. With Smith out, S Morgan Burnett had that responsibility.

McCarthy said that, against the Saints’ up-tempo offense, the defense wasn’t as “crisp and in sync” as it needed to be.

“Whether it was the communication from the sideline, just the whole mechanics of everything was not as clean as we would have liked,” McCarthy said. “And frankly, we got out of it because I think we were probably 1 out of 8 or 0 for 7, somewhere in there, as far as winning the down.

“We were not in tune. We changed who had the headset on. I think sometimes that stuff may look a lot easier than it is. It’s a little different when you have someone in your helmet, in your ear and you have to communicate it, the timing of it, the whole pace of it. It’s definitely something we can learn from.”

Neal set to return: Mike Neal has a one-week roster exemption this week coming off the reserve/suspended list, McCarthy said Monday.

Neal was suspended in the offseason for the first four games for violating the league’s banned substances policy. The third-year DE said he had been using the stimulant Adderall, for which he said he had a prescription. He hasn’t been at the team facilities or able to practice since the end of training camp, so McCarthy said the team would evaluate him for a full week to “see where he is.”

“I think it’s very important for Mike Neal to go through a week’s practice, McCarthy said. “We know Mike’s been working out. I’ve not seen him yet personally, but just knowing Mike, as far as his training habits, he’s always in top shape. It’s different. He hasn’t been practicing football for four weeks.”

Follow Packers reporter James Carlton on Twitter: @CBSPackers and @jimmycarlton88.