JUPITER, Fla. -- Marlins right-hander Sixto Sánchez has another four weeks before he can begin a throwing a program, MLB Pipeline's No. 58 overall prospect told a small group of reporters on Wednesday.

Optioned to Triple-A Jacksonville by the Marlins on Tuesday, Sánchez will continue to rehab his right shoulder, which he had surgery on last July 20 to repair a capsular tear and clean out the back side. The 23-year-old said he felt discomfort again approximately a month ago when he started to long toss, and he underwent an MRI that showed no structural damage.

Because Sánchez is a member of the 40-man roster, he was prohibited from communicating with the Marlins during the lockout. It appears to have had an effect on his rehab, which had been on track per a video released on Nov. 28 to the Marlins' YouTube channel. In it, he expected to be full go at Spring Training.

"When I was at home [in the Dominican Republic], I tried to do all the exercises similar to the ones that I was told here, but it wasn't the same," Sánchez said via an interpreter. "That's why I decided to come back here to the U.S. [on Jan. 7]. I was doing something separately. Again, it was not with the team. And it was not the same, many things that we were doing. Again, it was not feeling the same way."

It has been a tough road for Sánchez, who debuted with a 132 ERA+ in 2020 with help from a triple-digit fastball and a lethal changeup. Projected to open the 2021 season in the rotation, he instead experienced discomfort in a simulated game on March 31 -- nearly a year ago -- and was diagnosed with inflammation. His rehab stalled on and off before undergoing the shoulder procedure four months later.

"Once you're in rehab, you always want to get better and get back to the field, but unfortunately it's been something that every time I'll be moving forward, somehow I had a setback," Sánchez said. "I've just got to continue having a positive mindset and keep working just to get back on the field."

Asked whether he would be open to a bullpen role if it expedited his return and kept him healthy, Sánchez said he "wouldn't say no to that.

"But again, I started my career as a starter, and I made it to the Majors as a starter, and I would love to continue my career as a starter," Sánchez said.