Luck missed the entire 2017 season while rehabbing from shoulder surgery and there were speculation that the injury could threaten both this season and his career.
Through the first five games of the season, Luck has held up well -- despite Indianapolis' 1-4 record and the fact that he is on pace to set the NFL record for passing attempts in a season.
The Colts found themselves facing a big early deficit for the second time in as many games in Thursday's 38-24 loss to the New England Patriots.
Forced to play catch-up, Luck went to the air 59 times against the Patriots, completing 34 passes for three touchdowns and two interceptions.
That came four days after Luck threw for four touchdowns and a career-high 464 yards in a 37-34 overtime loss to the Houston Texans.
Luck was 40 of 62 against Houston, giving him a staggering 121 pass attempts in a five-day span.
"It's a lot," Luck told reporters after Thursday's loss. "We know we need balance. Football's not rocket science. You need to be able to run the ball well to help protect your passing game. We'll keep working at it and we have no excuses for it. We've got to get better. Everybody, including me, in it."
Luck is averaging 49 passes per game and is on pace to attempt 784 passes this season -- the league record is 727 by Detroit's Matt Stafford. He also is on pace for 521 completions, which would eclipse the previous mark of 471 held by Drew Brees of the New Orleans Saints.
The one positive for Luck is that he reported continued improvement in his game despite the heavy workload over the past week.
"I felt like I've gotten so much better every game. I really do. And maybe it shows to the naked eye a little better the past two games -- and at the same time, I know I have so much more to improve upon," said Luck. "I know I can be a better quarterback for this team and certainly some things do feel well out there. I think for a large percentage of those throws, the ball was going where I wanted it to go and all over the field. But there's still -- I feel I still have a large room, bunch of room for improvement."
Indianapolis coach Frank Reich also gave his quarterback high passing grades following Thursday's defeat.
"Yeah, he's playing really good, really good again tonight," said Reich. "Really played good football, threw the ball great, every kind of throw that you could throw. Very good decisions, playmaking, he played very good tonight."