INDIANAPOLIS -- Colts quarterback Andrew Luck acknowledged Monday that he originally injured his surgically repaired right shoulder during the 2015 season.

Luck and the Colts held off on the quarterback having surgery at the end of the 2015 season because they felt like rehab was the best route to go. But Luck decided to go ahead with the surgery this offseason after he aggravated the injury last season against Denver.

"I certainly felt like it was the right decision, which makes it easier and pulling the trigger on it easier," Luck said. "I felt very, very comfortable with the surgeon and his plan and our rehab plan here.

"This wasn't an off-the-cuff thing. I put a lot of thought, effort and plan in moving forward after the season -- talked to a lot of people and got quality information. Honestly, it wasn't too hard of a decision. It felt right."

The surgery on Luck's throwing shoulder is expected to keep him out of most of the team's nine-week offseason workout program. Neither Luck, coach Chuck Pagano nor general manager Chris Ballard has a definitive timetable on when he'll return to 100 percent.

Scott Tolzien will work with the first unit until Luck returns. Luck's goal is play in all 16 games next season.

"I made this decision based off all the information we could all find, that I could find," Luck said. "I have no regrets going to get surgery. I fully trust when the doctors say I'm 100 percent, that I'll be 100 percent no question."

Luck has shied away from talking about injuries in the past. But that changed Monday when he admitted that the injury originally occurred in the Colts' come-from-behind 35-33 victory against the Tennessee Titans in Week 3 of the 2015 season. Luck missed the next two games before returning and playing four straight games before a lacerated kidney ended his 2015 season.

Luck and the Colts decided rehabbing the shoulder was the best approach to take after that season. Owner Jim Irsay said during the team's trip to London last season that his franchise quarterback aggravated the injury while trying to make a tackle following an interception that was returned for touchdown by Broncos cornerback Aqib Talib in Week 2.

Luck, who wore a sling on his shoulder for part of the offseason, was listed as a full participant in 24 of the Colts' 48 practices last season.

"My practice schedule was different and altered -- that made things a little bit more difficult from a preparation standpoint," Luck said. "There were a couple of times during the year where I would get hit in an awkward position, in an awkward way. It wouldn't feel great and it would be a taxing effort to get ready for the next week."

Despite the injury, Luck still passed for 4,240 yards and 31 touchdowns while completing a career-high 63.5 percent of his passes in 15 games last season.