One of the most important parts of being an NFL quarterback is being able to throw a regulation-sized football, and right now, Andrew Luck still isn't able to do that. 

Although Luck has been throwing smaller footballs during his rehabilitation, the Colts quarterback revealed on Monday that he still hasn't thrown an actual NFL football. The last time Luck threw a football came in October, but the Colts ended up shutting him down for the season after he suffered a setback. 

"There's a process," Luck said Monday, via ESPN.com. "I've gone and skipped steps before and paid for it. Been in pain and not able to help the team. Embarrassed, guilty, whatever. I'm not going to do that again. I trust the people I'm working with. More importantly, I trust myself in this process. I trust how I feel. Progress is my guiding light. If I'm making progress, I know that's important. There is a plan in place and I'll keep trusting it."

Although Luck is hoping to be ready for training camp, he wouldn't reveal when he might be ready to throw an NFL football. 

"When the time is right, I'll pick it up," Luck said, via NFL.com. 

Luck has been throwing smaller footballs to work on his throwing motion. 

"I wouldn't say (I'm) changing my throwing motion," Luck said, via ESPN. "There are things in my throwing motion that I can do better from the ground up and that's a big part of what I've been working on, making sure I'm using my body as effectively as possible to throw a football and not over or under compensate in any way."

During the interview on Monday, which was his first one in nearly six weeks, Luck admitted that he's not "a perfect-feeling athlete right now."

If you're a Colts fan and that makes you nervous, it probably should. Luck's health has basically been a giant mystery since he underwent surgery in January 2017, and updates from the Colts have been all over the place. 

Back in June, Jim Irsay said that Luck's recovery was going "tremendously." Two months later, the Colts owner said that Luck would likely only miss one or two games. That prediction turned out to be slightly off because, instead of one or two games, Luck ended up missing the entire season. 

Since then, everyone in the Colts organization has been pretty shy about offering any sort of recovery timeline and Luck stuck to the company line during his Monday interview. The 28-year-old said that although there's a timetable for his recovery, he wasn't going to reveal it. 

"There is a timetable but I'm not going to share it with you guys," Luck said, via NFL.com. "I've very, very confident and very, very optimistic I'm going to be absolutely fine and come back better than I was. I'll be a better quarterback, a better teammate, a better person and I'm very confident."

The Colts quarterback hasn't played in a game since December 2016, and if he somehow does return to the field in time for Indy's 2018 opener, that will come a full 20 months after he originally underwent shoulder surgery. The good news for Luck is that plenty of quarterbacks -- including Tom Brady, Peyton Manning and Joe Montana -- have come back to play at a high level after missing an entire season due to injury.