Andrew Luck Watch 2018 is truly underway.

The Indianapolis Colts star quarterback's rehab from a shoulder injury that robbed him of the entire 2017 campaign will be one of the defining stories of the offseason.

Luck provided a substantial update Tuesday, ruling out a second surgery and confirming he has resumed throwing "a little bit" to strengthen his surgically repaired shoulder.

While Luck didn't go into specifics, NFL Network's Ian Rapoport reports the star signal-caller is throwing weighted balls heavier than footballs rather than tossing around a normal football.

It's a significant step for the 2012 No. 1 pick, who briefly returned to practice in November and was seen throwing before again experiencing pain in his shoulder, forcing Indy to place him on injured reserve.