Andrew Luck has informed the Indianapolis Colts that he is retiring from the NFL, a source told ESPN.

Luck, who turns 30 on Sept. 12, already has met with Colts owner Jim Irsay to tell him that he is retiring, the source said.

There will be a news conference Sunday to make it official, but Luck is mentally worn down, and now checking out, the source said.

The XFL has spent the past two years determining team locations, signing stadium agreements and hiring head coaches. Its teams will play in a combination of NFL, MLB and MLS facilities. The league office has sent hundreds of draft pool invitations to prospective players and last month announced its first signing: veteran quarterback Landry Jones.

Next up will be finalizing and publicizing a rulebook that the league says will offer a reimagined game of football, including unique extra points, a modified setup for overtime and a shorter play clock to accelerate game tempo.

A draft is scheduled for October, followed by a minicamp in December and training camp in January 2020.

Energy Star, the federal program from the DOE and the Environmental Protection Agency, said the coolest you should keep your home is 78 degrees when you're home.

When you're at work or away, the program recommends setting it at 85 degrees. When you're sleeping, Energy Star said to set the thermostat at 82 degrees.