BOSTON -- Rehabbing left-hander Patrick Sandoval isn't anywhere close to getting into a game for the Red Sox, but he's still making quite the impression on his new team.

Sandoval, who underwent an internal brace procedure on his pitching elbow in July, took an important step in his throwing program late last week when he got off the mound for the first time and threw his second bullpen session Tuesday at Fenway Park. His workouts before getting off the mound, though, have caught the attention of manager Alex Cora.

"The progress is a good one and it's not a coincidence," said manager Alex Cora. "This guy, he works. We talk about (Aroldis) Chapman. He's up there with him, as far as his work ethic. It's amazing. We call him "The Machine." Every time you walk into the weight room, he's there doing something. Him and (strength and conditioning coach) Kiyoshi (Momose), they have a great relationship. Excited about him."

Sandoval, a veteran of parts of six big league seasons with the Angels, signed a two-year, $18.25 million deal with the Red Sox in December. He signed with the Red Sox in the middle of the rehab process, so the deal was much more about 2026 than 2025. Still, Boston thinks the lefty can "hopefully" contribute down the stretch this season," according to Cora. Late last year, chief baseball officer Craig Breslow said the expectation is that Sandoval will be healthy in the second half of 2025.

Sandoval is one of four Red Sox rotation options currently on the injured list along with righties Richard Fitts, Tanner Houck and Kutter Crawford.

"I don't know when we're gonna have him," Cora said of Sandoval. "I don't know if it's going to be this year. Obviously, next year. But the way he goes about it, it has been great.

"He's enjoying the whole thing. He likes it here. He likes it a lot. He was able to go to the Garden for two (Celtics) games and was excited about the fan base and all that. A good guy who is working hard. It's amazing to see him."