Adam Schefter breaks down the consequences Odell Beckham Jr. will face after his touchdown celebration on Sunday. (0:55)

New York Giants co-owner John Mara said Tuesday that he isn't happy about Odell Beckham Jr.'s touchdown celebration in which the wide receiver simulated a dog urinating. Mara said the team would deal with the matter "internally."

Mara made his comments in an email sent to multiple media outlets.

He wrote: "I do not want to get into a discussion about this, but I will say that I am very unhappy with Odell's behavior on Sunday and we intend to deal with it internally."

On Sunday against the Philadelphia Eagles, after his scoring his first touchdown of the season, Beckham pretended to walk like a dog after the score and simulated urinating on the field. The Giants were penalized for Beckham's celebration.

He said after the Giants' 27-24 loss that he had no regrets.

"I'm a dog, so I acted like a dog. I don't know if the rulebook said you can't hike your leg. He said I peed on somebody, so I was trying to find the imaginary ghost that I peed on. But I didn't see him," Beckham told reporters.

On Monday, he responded to a fan on Twitter who asked if the celebration was related to President Donald Trump's recent comments about NFL player protests, Beckham wrote:

If u seen that , I have to tip my hat to u for thinkin outside the box. #URRIGHTONPOINT impressed — Odell Beckham Jr (@OBJ_3) September 25, 2017

Giants coach Ben McAdoo wasn't interested in discussing the celebration on Monday, other than expressing his displeasure that it cost the Giants yardage on the ensuing kickoff.

Eagles coach Doug Pederson called Beckham's celebration "unfortunate" and said it was something his team would "file away" for later.

The Giants and Eagles are scheduled to meet again on Dec. 17 in East Rutherford, New Jersey.

Quarterback Eli Manning said Tuesday that he didn't see the celebration and didn't know why the Giants were penalized. He also didn't feel the need to talk with Beckham in the days after the incident.

But he said he understood the criticism.

"Hey, that is part of football," Manning said. "You get penalized there are going to be people who are unhappy, whether it is the owner, the head coach or other players. You can't afford penalties."

Beckham's unsportsmanlike conduct was one of 10 penalties committed by the Giants on Sunday. Seven came in the fourth quarter.

Manning thinks they all need to do better, including Beckham.

"I want him to go out there and play hard. It's part of being smart in all aspects of penalties," Manning said. "I don't think unhappy is the word. Just everyone has to be a little smarter in this situation where things are tough and we have to get wins and we have to grind and we're catching some bad breaks and things aren't going our way -- we can't afford to make it harder on ourselves."

ESPN's Jordan Raanan contributed to this report.