McCoy's father, Horace McCoy, told The Los Angeles Times on Thursday that his son has been dealing with a fever since the summer, and doctors cannot explain what it is from.
"He's actually doing really well, a lot better," Helton said after the USC Football Fall Showcase on Saturday. "He's in meetings right now. He's doing everything except being out on the field with us. I even saw him today, and he's doing better. When he feels totally up to it, we'll start strength and conditioning with him, but he's heading in the right direction."
Doctors have treated McCoy for a variety of illnesses, but his father told The Times that doctors said he has a "fever of unknown origin."
"They cannot figure it out," Horace McCoy told The Times. "I cannot tell you how many specialists we've got him in front of, just to try to figure this damn thing out."
USC will not let Bru McCoy practice until the fever is gone. Helton wouldn't say if there has been an official diagnosis for McCoy's illness.
"I'm not going to do that, as far as medical things," Helton said. "I'm not going to go into privacy of a medical document, but he's doing well, and he's going to be well."
Helton also said that McCoy's waiver status for immediate eligibility is still "in process." The former No. 1-ranked athlete prospect in the 2019 recruiting class transferred to Texas after committing to and enrolling at USC in January. He then transferred back to USC after spring ball with the Longhorns.
Even without the dynamic McCoy on the field for a scrimmage that drew an announced crowd of 10,000-plus, USC had a pretty positive night offensively.
All four USC quarterbacks -- JT Daniels, Matt Fink, Jack Sears and Kedon Slovis -- played and led scoring drives during the 90-minute scrimmage. Daniels, Fink and Sears led two scoring drives, with Daniels tossing two deep touchdowns in the process.
"I thought they made great decisions today," Helton said of his quarterbacks. "You didn't see any forced balls, and they looked like [they had] great poise. Each one of them led long drives. I thought there was consistency and poise amongst all of them. It was nice to see, and that's what you hope to see as you're going into your third week of training camp."
Daniels started 11 games as a true freshman last fall and is the favorite to start for the Trojans when they open the season at home against Fresno State on Aug. 31 (10:30 p.m. ET, ESPN), but Helton said no decision has been made at the position. Helton plans to talk to new offensive coordinator Graham Harrell about the competition on Monday.
"We're going to look at this tape and see where we're at. I've never had four quarterbacks that could start on a lot of football teams across the country, and all of them are playing at a high level," Helton said. "It's really progressed everybody. I'm so glad that we have done this. I'm going to sit down with Graham on Monday ... grade this football tape and be ready for a great Tuesday practice and see where we're at."