MIAMI -- The Marlins hope top prospect Sixto Sánchez will be able to pick up a baseball again three months after undergoing season-ending arthroscopic shoulder surgery, general manager Kim Ng said Tuesday. A date has not been set for the procedure. Late last week, Sánchez experienced soreness as he increased velocity during his throwing program, with an MRI revealing a small tear in the posterior capsule of his right shoulder.

Miami expects Sánchez to be ready to participate in Spring Training in 2022. When asked whether winter ball could be an option for Sánchez, Ng said it was "probably not in his cards. I think that's a little too active."

This was the latest setback in a year full of them for MLB Pipeline's No. 11 overall prospect. The Marlins were counting on Sánchez to be part of their 2021 rotation after an impressive seven-start debut in 2020, when he flashed 100 mph heat and recorded a 132 ERA+. Entering the season, Miami had a plan for Sánchez to pitch into September, with an innings limit of around 165. Instead, one of the preseason favorites for the National League Rookie of the Year Award will not have thrown a pitch for the ballclub.

Ng said once Sánchez's MRI results came back, electing for surgery became the next step. The decision was made easier by the limited progress in Sánchez's rehab.

"I think with any type of situation like that, clubs, particularly with their young pitching, they're going to want to try and be very cautious and very conservative, and I've used that word all along," Ng said. "You want to try and avoid surgery. I think that we tried and unfortunately, it just didn't happen."

Here is a timeline of Sánchez's 2021 activities based on when the club provided updates:

March 15
Makes Grapefruit League debut, tossing 1 2/3 scoreless innings (31 pitches)

March 20
Throws three perfect frames in his second spring start (32 pitches)

March 25
Allows one run over 3 1/3 innings in his final Grapefruit League outing (61 pitches)

March 31
Experiences shoulder discomfort while throwing two-plus innings in a simulated game at the alternate training site in Jacksonville, Fla. An MRI later reveals right shoulder inflammation.

April 16
Throwing at 45 feet

April 22-26
Throwing at 60 feet

May 4
Throwing at 105 feet

May 18-21
Remained at 120 feet

May 25
Sánchez throws a 20-pitch bullpen. Ng notes on May 22 that the organization is being cautious with him because "we're in this for the long haul."

June 5
Experienced slight discomfort during throwing program in between bullpen sessions

June 8
Cleared to resume throwing on flat ground

June 11
Resumed throwing at 60 feet

June 14-18
Throwing at 75 feet

June 22-29
Throwing at 120 feet

"There's some things in order for me to move forward when he comes back that we've got to get a little more proficient, a little more out of the lower half [with his mechanics]," pitching coach Mel Stottlemyre Jr. told MLB.com Tuesday. "Through his rehab, there was a stall, him kind of cutting pitches off and not getting that full extension that just kind of led me to believe as I watched it, it's like there was something either in his mind that he didn't want to get to that point.

"Obviously this is a blow to our rotation, and to how we wanted to move forward with this season. My first instinct is, 'All right, he gets the surgery. We get him back, and then we definitely have to address a few mechanical things.' Again, the job that player development did in getting him more efficient and creating more body awareness."

The 22-year-old right-hander was set back twice during the spring, first with a late arrival to camp because of a visa issue out of the Dominican Republic, and then due to a false COVID-19 positive test.

Miami has been careful with Sánchez since acquiring him from the Phillies in the trade for catcher J.T. Realmuto in February 2019. He was limited to eight starts at the Class A Advanced level in 2018 because of right elbow inflammation. In spring 2019, he did limited work, then arrived the following camp out of shape.

"First, let me say, you feel bad for him before the organization," CEO Derek Jeter said. "It's still a young man that is starting his career. He obviously had some soreness there, so he took more tests, and hopefully you fix it, and you move on. You've got to look at the big picture. You hope that he has a very, very long career and this is just a minor setback. But you wish the best for him as a player. The organization goes on. But as a player, your career is only so long, so hopefully he comes back stronger."