Indianapolis Colts first-year head coach Chuck Pagano has been diagnosed with a treatable form of leukemia, according to sources.

The sources said Pagano waited until the Colts' bye week last week to be checked out after experiencing extreme fatigue and bruising, starting in training camp.

Pagano believed he was experiencing football fatigue, but a blood test early last week revealed the diagnosis of leukemia.

Pagano has been in lock down in an intensive care unit of an Indianapolis-are hospital since last Wednesday, where he has been receiving treatment.

The sources said Pagano will be out a minimum of six weeks, but that he plans to return as coach.

The Indianapolis Star is reporting that offensive coordinator Bruce Arians will serve as the interim coach in Pagano's absence.