It didn't come from the gathered media.
Kelly stopped in midthought, pulled his NFL Network cap down over his head and reached into his pocket for the offending phone.
"I don't know what this is," Kelly said while flashing a sheepish smile.
"I can't can't even get a press conference straight."
If Kelly is sweating after the Eagles lost two consecutive games since his dynamic NFL debut victory, he's not letting it show.
The Eagles lost and it annoys him, but he also knows that the Birds now have 9 days before they get back on the field at the Denver Broncos on Sept. 29.
The thing he is focusing on is how he, his coaching staff and players can correct the mistakes they have made since their near-perfect first half against Washington and how they can prepare to face future Hall of Fame quarterback Peyton Manning and the Broncos.
"The people that are going to fix this were in our locker room [Thursday] night," Kelly said. "That's our coaches and our players.
"The one thing I do know is that you can't feel sorry for yourself. That's not going to solve any problems.
"It's about getting to work and understanding that mistakes are made, but if you continue to make the same mistake, that's when we really have an issue. Let's fix what we saw went wrong on Thursday night and try to build upon it."
Because it is the Eagles and Kelly is the new coach after 14 seasons of Reid, every point and counterpoint he makes will be scrutinized.
Now, the talk for the next 9 days will be what, how or whether Kelly can get the Birds back together and correct many of the flaws that caused them to lose the last two games.
That would be the same for any other coach in this situation, but because Kelly has that college-to-the-NFL thing going on, it had another dynamic.
One of the big issues right now is that Kelly has had no actual experience of his team getting off to a bad start.
He lost his head-coaching debut at Oregon, but the Ducks then rolled off seven consecutive wins before losing to Stanford.
That 7-2 start was the worst Kelly had in his four seasons leading the Ducks. His only two-game skid as Oregon's head coach was losing the 2010 season BCS title game to Auburn and losing the 2011 season opener to LSU.
But if we're being honest with ourselves, we're not actually judging Kelly by what he might or might not do as the Eagles' coach.
We're extrapolating from the failures of other coaches who could not make a successful jump from college to the NFL and searching for signs that Kelly might be repeating some of their trends.
Kelly is being graded on an unfair curve. What Steve Spurrier, Nick Saban or Bobby Petrino did has no legitimate impact on what Kelly might do.
Funny that when we talk about the college coaches who failed, we have conveniently forgotten how Jim Harbaugh came to the NFL after his head-coaching experience was only at the University of San Diego and Stanford University.
All Harbaugh did was take the San Francisco 49ers to the NFC Championship Game in his first season and Super Bowl XLVII in his second.
On the positive side for Kelly is that if he were still at Oregon, a 1-2 start would have ended his chances for a BCS title before October. This is not a good start in the NFL, but there is still time to make the playoffs if you can right things - and that's a big if for a team such as the Eagles that just doesn't seem to have enough talent The interesting thing is that if you listen to Kelly, his basic approach is quite simple.
"The game of football comes down to it, no matter how you want to slice it, one-on-one battles," he said. "The Kansas City Chiefs did a better job on the one-on-one battles than the Philadelphia Eagles.
"In this league, winning football games is a difficult task. I think everybody understands that.
"It's really about getting your mindset into a rhythm that every week is a season. Whether you won or lost last week is really irrelevant to moving forward.
"If you win, you don't get to pat yourself on the back too long, because the next team coming is hunting for you.
"If you lose, you can't be licking your wounds too long, because the next team is hunting for you."
It's going to be that kind of season for Kelly. Through no real fault of his own, he has been labeled as a coach to watch and have every decision analyzed front, back and sideways.
The next 9 days are about seeing how Kelly handles his first NFL losing streak.
"So we need to continue to move on," said Kelly, who gave his players the weekend off. "I know from the amount of time I've been around this group, I know they will come back on Tuesday.
"They'll be ready to go to work. Can't face a bigger challenge than playing the Broncos in Mile High Stadium. That will get our attention. We'll be ready to play."
And if the Eagles aren't ready to play, everyone will let Kelly know.