His absence left his teammates to speak for him, even if they were reluctant to talk about the night in question.
Still, tight end Vernon Davis said a larger number of 49ers players were at the party Saturday night in which the alleged incident between McDonald and his girlfriend took place.
"I'm not sure if it was half [the team] or 75 percent," he said. "I know guys came to support Ray on his birthday. We love each other so we have to support each other."
But as to factual details of the goings-on at Bentley Ridge Drive in San Jose?
"I was actually leaving, on my way out, and I saw the cops around," said Davis, who initially posted a photo on his Instagram account celebrating the party, before taking it down, "Just because," he said.
"As far as what went on, I don't really know. I wish I could tell you guys something.
"I didn't see anything. I didn't hear anything. So I don't know what went on over there. I wish I could put my finger on it. I don't know. All I do know is Ray is a great guy. He's awesome. He has great character. Everyone on the team knows that. He's a guy of good integrity, great character, hard worker, good player. He comes to work each and every day."
Including, apparently Tuesday, as he was reportedly allowed to practice.
But if and when McDonald is hit with a six-game suspension under NFL commissioner Roger Goodell's more stringent domestic violence policy, it will be another blow to the 49ers' already weakened defense.
Inside linebacker NaVorro Bowman is out for at least six games as he recovers from a knee injury suffered in the NFC title game. Aldon Smith was hit with a nine-game suspension for numerous transgressions. And nose tackle Glenn Dorsey was placed on the Injured Reserve/Designated to Return list on Monday as he continues to rehab from his torn left biceps.
"I mean, losing those guys ... you can look across the board and find every reason to run the other way or make excuses as to why you may not be as good or why we can't be as good, but at the end of the day, you're only as good as the guys that are out there on the field anyway," said inside linebacker Patrick Willis. "So whether it's a guy that goes down with injury or whatever reason a guy can't be out there, whether he's taking some plays off, it's about the guys that's out there on the field playing.
"For us, all these guys have our support, injured, situations, whatever they may be. At the end of the day, we just got to win ballgames."
Coach Jim Harbaugh earlier in the day reiterated his zero-tolerance policy for domestic violence in a radio interview on KNBR.
"If someone physically abuses a woman and/or physically or mentally abuses or hurts a child, then there's no understanding," he said, "there's no tolerance for that."
The message was given again to the team on Tuesday.
"Everybody knows domestic violence is a bad thing, and he does tell us he's not tolerating stuff like that," said linebacker Corey Lemonier. "He emphasized it today.
"That's distractions. We have a game this weekend and we're just trying to focus on that and not let us get deterred about these things."
Said Willis: "We never condone anything of this magnitude, but it is what it is and nobody knows [the full story], you know, there's two sides to every story. So we just hope that everything gets situated and we can get right back out on the field and everybody can be at peace."