Colts head coach Chuck Pagano has been diagnosed with leukemia and will probably not return to the sidelines this season, the team announced Monday morning.
Leukemia is a cancer of the bone marrow. The first phase of treatment typically lasts four to five weeks, requiring a hospital stay for most of that time.
Pagano, 51, had been feeling fatigued in recent weeks and got blood tests during the bye week.
The leukemia is treatable, and Pagano will spend four to six weeks in the hospital with initial treatment. He plans to eventually return as coach.
"I feel with every fiber in my body, and Chuck feels the same way, that he can beat this thing," said Colts owner Jim Irsay.
While Pagano is recovering, offensive coordinator Bruce Arians will take over as the team’s head coach.
"He (Pagano) was brought here to bring this team to greatness. That plan has not changed," said Colts general manager Ryan Grigson.
"Chuck has laid a foundation here that is on rock solid ground," Arians said. "We will continue his fight."
Irsay said the organization is coming to grips with Pagano's diagnosis. Arians, himself a cancer survivor, choked up when he said the light would be left on in Pagano's office until his return.
"He's a salt of the earth man. You aspire to be the type of man he is. He's the type of guy who goes out of his way to treat people in a special way. He's going to be greatly missed. There's no question about it," Irsay said. "He has set the tone for the players, for the coaches, and what he expects. We will pull together. It's been a very difficult day -- a lot to take in for our coaches, our players and our organization."
Depending upon the success of his treatment, Pagano could be allowed to return in a limited role, possibly in the press box, later in the season.
"It's unlikely he will be all in as a head coach this season. That's probably not in the cards that he will be able to come back and be all in," Irsay said.
Dr. Larry Cripe, a hematologist, is treating Pagano.
"The goal of the treatment is to cure the disease," Cripe said. "The process is long and complicated, and we're just starting right now."
Cripe said Pagano is doing well so far and that "his spirits are good."
Irsay said there was silence and tears when players were told of Pagano's diagnosis Monday morning.
"It's just shock. It's a lot to hear," Irsay said. "You hear something like this, and it's just stunning."
Pagano was hired as Colts head coach in January 2012. He previously worked as the defensive coordinator for the Baltimore Ravens and held positions with the Cleveland Browns and the Oakland Raiders.
Pagano and his wife, Tina, have three daughters, Tara, Taylor and Tori, and two granddaughters, Avery and Addison, according to his profile on the Colts' website.