McCluster is one of approximately 26 players who will miss practice Wednesday, after about 20 missed practice Tuesday.
"Jevan no longer has a fever," Mullins said. "We're keeping him hyrdrated and he's feeling better today. We are monitoring them all closely. We're checking their temperatures two or three times a day. They're isolated as much as they can be."
So many players were out Wednesday coaches moved practice up and shortened it. Still, they were shuffling the lineup all day.
"Boy, it's tough," Ole Miss offensive coordinator Kent Austin said. "We lost another quarterback today, too, so we're down to Nathan Stanley and Clayton Moore. About half our receiving corps is out, half our starting line."
Mullins declined to give extensive details on the symptoms that led McCluster to be hospitalized, but said he is recovering well.
According to Ole Miss spokeswoman Barbara Lugo, as of Wednesday morning, 381 students had reported flu-like symptoms at the school.
Ole Miss is going under the assumption that all are H1N1 though in most cases testing will never occur. Students, including athletes, are being asked to go home or remain isolated, are being asked to drink plenty of liquids, to use hand sanitizers and wash their hands frequently.
Meanwhile, at Wisconsin, about 10 players were suffering from flu-like symptoms on Wednesday, according to director of sports medicine Dennis Helwig.
Wisconsin hosts Fresno State this weekend but the team was not in full pads on Tuesday. The team also cut practice short by a half-hour.
"We're only going to miss a few guys here as we start to get them back," Wisconsin athletic director Barry Alvarez said Wednesday. "I just came from the training room and they're starting to feel better. You don't know who might get sick before game time, of course. But you do what you can to get them healthy. And you stay mentally positive. They have to be in a positive mindset throughout the week and headed into the game."
A spokesperson who checked with coach Bret Bielema on Thursday said that only a few players were expected to miss practice at 6:20 p.m. ET. One player who has recovered from symptoms is starting left tackle Gabe Carimi, who is practicing.
Wisconsin has tested some players for H1N1 but has not gotten back confirmations yet.
McCluster also plays tailback and lines up at quarterback in the Mississippi's Wild Rebel formation. He opened the season in a 45-14 win over Memphis on Sunday with 65 yards receiving, 50 yards rushing and two touchdowns.
Austin said the situation isn't as dire for the Rebels as it is for other teams with a game to play Saturday.
"It's an opportunity to get the young kids a lot of reps," he said. "From that standpoint it's a positive. And the other good news is it's happening in a bye week. I'd hate the think if we were playing this week."
ESPN's Joe Schad and The Associated Press contributed to this report.