Indianapolis Colts head coach Chuck Pagano diagnosed with leukemia

Indianapolis, IN (Sports Network) - Indianapolis Colts head coach Chuck Pagano has reportedly been diagnosed with a treatable form of leukemia.

According to the Indianapolis Star, Pagano underwent blood tests last week after feeling fatigued in recent weeks. The paper did not initially speculate on the nature of the illness, but added that the Colts are optimistic about his recovery and will have a press conference on Monday to discuss details.

ESPN then reported that Pagano has leukemia and will miss the next six weeks.

Colts owner Jim Irsay, on his Twitter feed, did not reveal specifics about Pagano's illness, but acknowledged the coach's upcoming battle.

"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 tweeted.

The Colts had their bye this past week and will face Green Bay next Sunday.

Offensive coordinator Bruce Arians is expected to take over the head coaching duties in Pagano's absence.

Pagano, who will turn 52 years old on Tuesday, is in his first season as Colts head coach.