Notre Dame will resume team practices Wednesday after reporting 18 positive coronavirus tests on Monday, but the program has changed the way it will eat its pregame meals and will now have rapid antigen tests available on the sideline because of lessons learned from their outbreak, coach Brian Kelly told ESPN on Tuesday.

Kelly said team doctors determined that the outbreak, which resulted in 25 players in isolation and 14 others in quarantine, stemmed from two events surrounding the Sept. 19 game against South Florida: eating their pregame meal together, and one player who threw up on the sideline during the game and was treated for dehydration.

Kelly said the change in routine from summer camp to game week revealed new challenges that could have only been discovered with the start of the season.

"Throughout our entire time together, we had not had one meal where we sat down together," Kelly said. "Everything was grab and go. We get into our game situation where we have pregame meal together, and that cost us. Big. We had somebody who was asymptomatic, and it spread like wildfire throughout our meeting area where we were eating and then it got guys in contact tracing."

Kelly said the team will now eat its pregame meals at a convention center that has large ballrooms where it's easier for the players to stay at least 6 feet apart and not have any face-to-face contact. Kelly said he has to wear a microphone to be heard in such a large space.

"It's a reality we're living with," Kelly said, "and if you want to play football, you've got to make some adjustments along the way."

The player who threw up during the South Florida game didn't have a concussion or any other injuries, Kelly said, so the medical staff treated him for dehydration. The player then tested positive Monday, Kelly said.

"In trying to discern the difference between somebody who may be dehydrated in a game and having the effects of COVID on the sideline, [it] becomes very tricky," Kelly said. "Just being vigilant and understanding that this thing can hide in so many different areas make it a tricky proposition, even if you're doing all of the right things.

"We have to think about giving antigen tests on the sidelines for stuff that we never thought of," Kelly said. "That's the kind of shifting sands in this whole thing, learning in-game what do you do, what don't you do. We test Friday nights, too, so you're hoping your PCR test is getting that, but it's still a 50-50 proposition if you're cooking over that time, so there's still a little bit of uncertainty."

Notre Dame's 18 positive tests came from a round of 273 tests that were conducted between Tuesday and Saturday. Kelly said he expects almost 90% of the team to be able to practice by Saturday. He said they have been having Zoom position meetings, conditioning in smaller groups, and watching game film in preparation for their Oct. 10 game against Florida State.

Notre Dame started out 2-0 with wins over Duke and South Florida, but had its Sept. 26 game against Wake Forest postponed until Dec. 12. The Irish have a bye week, and Kelly said that in his 30 years of coaching he has never started a season and then stopped for two weeks.

"They can rebound from this, but it's not the ideal situation," Kelly said. "You don't want to start your season and then have to take a few weeks off. From that perspective, we've got to get our timing back, and certainly we'll have to have a great week of practice, and we expect to be able to do that."

Kelly said one encouraging lesson from this outbreak was that Notre Dame believes there wasn't a lot of on-field transmission, if any, to South Florida. He said because of that, he believes "college football is in good shape."

"Having gone through what we went through, we're feeling pretty confident that that's not going to be the area that we need to keep an eye on," Kelly said. "The area we need to continue to keep an eye on and be vigilant is your own team as it relates to social distancing, masks, when you're eating, things of that nature.

"The basic parameters of this are still in play, and you've got to be diligent with them, even when it's right up to game time, and that's the lesson we learned."