No one expected to hear the news on Saturday night that Andrew Luck was announcing his retirement -- in the middle of a Colts preseason game, no less -- but that development delivered a shockwave to the NFL landscape.

At just 29 years old, the Colts quarterback promptly decided to call it quits due to the physical and mental toll of several injuries suffered during his career. Luck, who was taken with the top overall selection in the 2012 NFL Draft, retires with 86 career games to his record, all with Indianapolis. He compiled a 53-33 career record, tallying 171 touchdowns and 23,671 passing yards against 83 interceptions. He finishes with a career passer rating of 89.5. 

Luck at his best proved to be the franchise quarterback the Colts hoped they'd get when they selected him to succeed Peyton Manning behind center. But a slew of injuries forced Luck to miss extended periods of time and those ailments clearly took a toll on the quarterback's psyche, and apparently he's had enough of the NFL lifestyle. 

Andrew Luck's shocked the world, so Will Brinson, John Breech, Ryan Wilson and Sean Wagner-McGough fired up an emergency Pick Six NFL Podcast to break down ever conceivable angle from the news. Can Luck be considered a bust? Who is to blame here? What does this mean for the Colts in fantasy and their win total for 2019? Listen in the player below and subscribe to the podcast here.

Here's a look at the timeline of Luck's physical issues since entering the league.

September 2015: Sprained shoulder

After playing three full seasons in Indianapolis, Luck ran into his first significant injury in Week 3 of 2015. He suffered a sprained shoulder during a game against the Tennessee Titans, though he was able to finish the contest and lead the Colts to a dramatic 35-33 comeback win. 

After that victory, Luck missed the next two weeks as he recovered from the injury. It would eventually lead to more issues down the line.

November 2015: Lacerated kidney, partially torn abdominal muscle

After getting back on the field following the shoulder injury, Luck didn't last long. Just a month later, he once again fought through injuries to deliver a gutsy win, this time against the Denver Broncos. But this time, there was no quick recovery. 

Luck woke up the next morning and noticed there was blood in his urine. He had suffered a lacerated kidney and a partially torn ab muscle during the Colts' win over Peyton Manning's Broncos, and he wouldn't take another snap the rest of the year after that victory. 

January 2016: Reports of torn cartilage

After the 2015 season, it was reported by Stephen Holder of the Indianapolis Star that Luck suffered torn cartilage in his ribs during the Week 3 contest in which he suffered the shoulder injury. When Luck returned to the field a few weeks later, he was playing through "significant pain" with the help of numbing injections. 

November 2016: Concussion

After a November win against the Titans, Luck was placed in the NFL's concussion protocol. He apparently suffered a concussion during that victory but stayed in the game. He missed the following week's game -- a Thanksgiving matchup against the Steelers -- but returned to action one week later.

January 2017: Shoulder surgery

After a 2016 campaign in which Luck reportedly struggled with his shoulder health, he underwent surgery in January of 2017 in order to repair damage to his labrum. Despite the lingering shoulder issues, Luck still had a pretty decent 2016 campaign for Indy, starting 15 games and throwing for 4,240 yards and 31 touchdowns against 13 interceptions.  

November 2017: Placed on IR, shut down for season

After undergoing surgery, there was plenty of uncertainty surrounding Luck's status heading into the 2017 season. Although he seemed to be trending towards a return at points, the Colts eventually placed him on IR and shut him down for the season following setbacks suffered during his shoulder rehab. When all was said and done, he didn't play at all during 2017.

August 2018: Finally returns to action

At long last, Luck was cleared to play and returned to the field for the Colts in a preseason game against the Seattle Seahawks -- his first game action since 2016. He completed 6-of-9 passes for 64 yards in the exhibition contest.

March 2019: Calf strain

Back in March of this year, Luck underwent an MRI that revealed a calf strain in the quarterback's right leg. There was quite a bit of mystery surrounding Luck's diagnosis, but he sat out parts of the Colts' OTAs in May and June, then carried the leg issue into training camp. 

As he continued to sit out, Luck was candid about being cautious with his health -- especially after some of his previous struggles. 

"I could not live with myself if we get to a point in the season and say, 'Hey, I could've done this to take care of this issue, but I didn't because of X, Y, Z, whatever that is,'" Luck said, via Business Insider. "I'm not going to allow that to happen. It's something, again — 2016. I still have some emotional scars from that and that lives with me still, but I'm trying to use it in a positive way certainly for myself."