Still, many of the players echoed Mornhinweg's and owner Jeffrey Lurie's sentiment, made the day before, that Reid will be back sooner rather than later.
"I think that is just Andy," center Jason Kelce said. "We got guys who lose relatives all the time on the team and they're gone for a significant amount of time, and Andy loses a son and he's talking about being back already.
"That just goes to show his level of, I guess, manhood, really. That's the best way you can say it."
In Reid's absence, Mornhinweg and defensive coordinator Juan Castillo have run practices. The Eagles have an off day Tuesday - the day of Garrett Reid's funeral services - and return to training camp at Lehigh University on Wednesday for a short mock game.
"We haven't talked about the challenge," Mornhinweg said. "We've talked about, simply, our responsibility, [which] is doing our job."
The Eagles open their preseason schedule Thursday night when they host the Pittsburgh Steelers at Lincoln Financial Field. The private Reid may prefer to get the media obligations that will surely be overwhelming out of the way Wednesday, when the Eagles' practice is closed to fans.
The team, meanwhile, went about its business Monday. That's the way Reid said he wanted it.
"He kind of just told me, 'Keep this thing rolling. Keep everybody on track. We can't use this as a setback right now. If anything, we need to go forward on this,' " Kelce said.
There was a morning walk-through and then a full practice in pads in the afternoon. The familiar sight of Reid in his all-black gear and white Eagles cap has been missing the last two days. So, too, was his commanding presence.
"Well it is totally different," wide receiver Jason Avant said. "I think Marty did a great job. I think Marty was definitely a godsend yesterday because he calls us to focus. But the warm-ups and the walk-throughs were totally different than I have ever experienced around here."
Monday afternoon's session was a sloppy affair, with many errors, particularly during a team drill in which the offensive and defensive lines took turns jumping offsides on four successive plays.
Reid would typically walk to the line of scrimmage to either assign blame or correct the offender in his taciturn way. Mornhinweg preferred to stand back, and when the offense had its last false start he merely called for the second team to take over.
Reid will return at some point, that is certain. The question that has been hovering over the Eagles since Garrett Reid's death is how the loss of his son will affect Reid and, in turn, this most important season for the coach.
The Reids acknowledged Monday evening that their son's death was related to his "long struggle" with drug addiction. Andy Reid had kept his son close to him since his release from prison in 2009, allowing him to eventually work with his strength and conditioning staff. And now his son is gone.
"He's always so close to him," Kelce said. "He's been holding him under his wing for so long in the organization."
Many players said that after the initial shock, they have banded together in the name of their coach - even though he currently isn't with them.
"This is an important time of year for us where we put everything together, but we understand that [Reid] has to do what he has to do," safety Kurt Coleman said. "We're going to be the backbone to help him get through what he needs to get through, and we'll always be here to support him."
Contact Jeff McLane at 215-854-4745, firstname.lastname@example.org, or on Twitter @Jeff_McLane.