Indianapolis Colts head coach Chuck Pagano was diagnosed with leukemia and will be away from the team for several weeks. Offensive coordinator Bruce Arians has been named interim head coach.
Pagano began feeling extreme fatigue during the Colts' bye week and had blood work done to find the cause.
Pagano has acute promyelocytic leukemia and the American Cancer Society website says early diagnosis is vital to patients making a full recovery. If detected early, the disease is considered treatable with remission induced in 80 to 90 percent of patients.
Patients with APL might develop serious blood-clotting or bleeding problems, according to the web site.
Pagano said in an email to NFL Network's Albert Breer that he would be "back real soon."
Owner Jim Irsay voiced his support for the first-year head coach via Twitter.
"Colts n all NFL Fans...keep Coach Chuck n his family in your prayers..He is fighting with courageous energy n faith and WILL win this battle," Irsay said via Twitter.
The Colts plan to hold a press conference later Monday.
Pagano turns 52 on Tuesday.
He was hired by general manager Ryan Grigson to replace Jim Caldwell. Previously Pagano served as defensive coordinator of the Baltimore Ravens.